Rollback

Chapter 1

It had been a good life.

Donald Halifax looked around the living room of the modest house that he and his wife Sarah had shared for sixty years now, and that thought kept coming back to him. Oh, there had been ups and downs, and the downs had seemed excursions into the flames of hell at the time—the lingering death of his mother, Sarah’s battle with breast cancer, the rough periods their marriage had gone through—but, on balance, when all was said and done, it had been a good life.

When all was said and done.

Don shook his head, but it wasn’t in sadness. He’d always been a realist, a pragmatist, and he knew there was nothing left now but summing up and looking back. At the age of eighty-seven, that’s all anyone had.

The living room was narrow. A fireplace was built into the middle of one of the long walls, flanked by autopolarizing windows, but he couldn’t remember the last time they’d actually had a fire. It was too much work getting one going and then cleaning up afterward.

The mantel held framed photos, including one of Sarah and Don on their wedding day, back in 1988. She was wearing white, and he was in a tuxedo that had been black in reality but looked gray here, having faded, along with the rest of the photograph. Other photos showed their son Carl as a toddler and again graduating with his M.B.A. from McGill, and there were two pictures of their daughter Emily, one when she was in her twenties, and another, holographic one, from her early forties. And there were several holos of their two grandchildren.

There were also a few trophies: a pair of small ones that Don had won in Scrabble tournaments, and the big one Sarah had been given by the International Astronomical Union. He couldn’t remember the wording on that one, so he walked over, taking small steps, and had a look:

He nodded, remembering how proud he’d been that day, even if her fame had briefly turned their lives upside down.

A magphotic flatscreen was mounted above the mantel, and when they weren’t watching anything it displayed the time in boxy red numerals a foot high, big enough that Sarah could see them from across the room; as she’d often quipped, it was a good thing that she hadn’t been an optical astronomer. It was now 3:17 in the afternoon. As Don watched, the remaining segments in the rightmost digit lit up; 3:18. The party was supposed to have begun at 3:00, but no one was here yet, and Sarah was still upstairs getting ready.

Don made a mental vow to try to not be short with the grand-children. He never meant to snap at them, but somehow, he always did; there was a constant background level of pain at his age, and it frayed his temper.

He heard the front door opening. The house knew the kids’ biometrics, and they always let themselves in without ringing the bell. The living room had a short staircase at one end that led down to the entry way and a taller one at the other going up to the bedrooms. Don walked over to the base of the one going up. “Sarah!” he called. “They’re here!”

He then made his way to the other end of the room, each foot-fall punctuated by a tiny jab of pain. No one had come up yet—this was Toronto in February, and, global warming be damned, there were still boots and jackets to be removed. Before he reached the top of the stairs, he’d sorted out the melee of voices; it was Carl’s crew.

He looked at them from his elevated vantage point and felt himself smiling. His son, his daughter-in-law, his grandson, and his granddaughter—part of his immortality.

Carl was bent over in a way Don would have found excruciating, pulling off one of his boots. From this angle, Don could clearly see his son’s considerable bald spot—trivial to correct, had Carl been vain, but neither Don nor his son, who was now fifty-four, could ever be accused of that.

Angela, Carl’s blond wife, was ten years younger than her husband. She was working to get the boots off little Cassie, who was seated on the one chair in the entryway. Cassie, who took no active role in this, looked up and saw Don, and a huge grin spread across her little round face. “Grampa!”

He waved at her. Once all the outerwear was removed, everyone came upstairs. Angela kissed him on the cheek as she passed, carrying a rectangular cake box. She went into the kitchen. Twelve-year-old Percy was up next, then came Cassie, pulling on the banister, which she could barely reach, to help her get up the six steps.

Don bent low, feeling twinges in his back as he did so. He wanted to lift Cassie up, but that was impossible. He settled for letting her get her little arms around his neck and giving him a squeeze. Cassie was oblivious to the fact that she was hurting him, and he endured it until she let go. She then scampered through the living room and followed her mother to the kitchen. He turned to watch her and saw Sarah coming down from upstairs, one painful step at a time, gripping the banister with both hands as she did so.

By the time she reached the bottom step, Don heard the front door opening again, and his daughter Emily—divorced, no kids—coming in. Soon enough, everyone was crowded into the living room. With his cochlear implants, Don’s hearing wasn’t bad under normal circumstances, but he couldn’t really pick out any one thread of conversation from the hubbub that now filled the air. Still, it was his family, all together. He was happy about that, but—

But it might be the last time. They’d gathered just six weeks ago for Christmas at Carl’s place, in Ajax. His children and grandchildren wouldn’t normally all get together again until next Christmas, but—

But he couldn’t count on there being a next Christmas; not at his age…

No; that wasn’t what he should be dwelling on. Today was a party, a celebration. He should enjoy it, and—

And suddenly there was a champagne flute in his hand. Emily was circling the room, handing them out to the adults, while Carl presented plastic tumblers of juice to the children.

“Dad, go stand by Mom,” Carl said. And he did so, making his way across the room to where she was—not standing; she couldn’t stand for long. Rather, she was seated in the old La-Z-Boy. Neither of them ever reclined it anymore, although the grandkids loved to operate the mechanism. He stood next to Sarah, looking down on her thinning snow-white hair. She craned her neck as much as she could to look up at him, and a smile crossed her face, one more line in a landscape of creases and folds.

“Everybody, everybody!” shouted Carl. He was the elder of Don and Sarah’s kids and always took charge. “Your attention, please!” The conversation and laughter died down quickly, and Don watched as Carl raised his own champagne flute. “I’d like to propose a toast. To Mom and Dad, on their sixtieth wedding anniversary!”

The adults all raised their glasses, and, after a moment, the kids imitated them with their tumblers. “To Don and Sarah!” said Emily, and, “To Grandma and Grandpa,” declared Percy.

Don took a sip of the champagne, the first alcohol he’d had since New Year’s Eve. He noted his hand was shaking even more than it normally did, not from age but with emotion.

“So, Dad, what do you say?” asked Carl. He was grinning from ear to ear. Emily, for her part, was recording everything with her datacom. “Would you do it all over again?”

Carl had asked the question, but Don’s answer was really for Sarah. He set his glass on a little tea table next to the La-Z-Boy, then slowly, painfully, lowered himself onto one knee, so that he was at eye level with his seated wife. He reached over, took her hand, feeling the thin, almost translucent skin sliding over the swollen joints, and looked into her pale blue eyes. “In a heartbeat,” he said softly.

Emily let out a long, theatrical, “Awwww…”

Sarah squeezed his hand, and she smiled at him, the same wry smile he’d fallen for back when they were both in their twenties, and she said, with a steadiness that her voice almost never managed these days, “Me, too.”

Carl’s exuberance got the better of him. “To another sixty years!” he said, lifting his glass again, and Don found himself laughing at the ridiculousness of the proposition.

“Why not?” he said, slowly rising again, then reaching for his glass. “Why the heck not?”

The phone rang. He knew his kids thought the voice-only phones were quaint, but neither he nor Sarah had any desire to have 2-D picture phones, let alone holophones. His first thought was not to answer; let whoever it was leave a message. But it was probably a well-wisher—maybe even his brother Bill calling from Florida, where he wintered.

The cordless handset was on the other side of the room. Don lifted his eyebrows and nodded at Percy, who looked delighted to be charged with such a task. He raced across the room, and rather than just bringing over the handset, he activated it and very politely said, “Halifax residence.”

It was possible that Emily, standing near Percy, could hear the person on the other end of the line, but Don couldn’t make out anything. After a moment, he heard Percy say, “Just a sec,” and the boy started walking across the room. Don held out his hand to take the handset, but Percy shook his head. “It’s for Grandma.”

Sarah looked surprised as she took the handset, which, upon recognizing her fingerprints, automatically cranked up its volume. “Hello?” she said.

Don looked on with interest, but Carl was talking to Emily while Angela was making sure her children were being careful with their drinks, and—

“Oh, my God!” exclaimed Sarah.

“What is it?” asked Don.

“Are you sure?” Sarah said, into the mouthpiece. “Are you positive it’s not—No, no, of course you’d check. Sorry. But—my God!”

“Sarah,” said Don, “what is it?”

“Hang on, Lenore,” Sarah said into the phone, then she covered the mouthpiece with a trembling hand. “It’s Lenore Darby,” she said, looking up at him. He gathered he should know the name, but couldn’t place it immediately—the story of his life, these days—and his face must have conveyed that. “You know,” said Sarah. “She’s doing her master’s; you met her at the last astro-department Christmas party.”

“Yes?”

“Well,” said Sarah, sounding as though she couldn’t believe that she was uttering these words, “Lenore says a reply has been received.”

“What?” said Carl, now standing on the other side of her chair.

Sarah turned to face her son, but Don knew what she meant before she spoke again; he knew precisely what she meant, and he staggered a half-pace backward, groping for the edge of a book-case for support. “A reply has been received,” repeated Sarah. “The aliens from Sigma Draconis have responded to the radio message my team sent all those years ago.”

Chapter 2

Most jokes get tired with repetition, but some become old friends, causing a smile whenever they come to mind. For Don Halifax, one such was a quip Conan O’Brien had made decades ago. Michael Douglas and Catherine Zeta-Jones had just announced the birth of their baby girl. “Congratulations,” O’Brien had said. “And if she’s anything like her mother, right now her future husband is in his mid-forties.”

There was no such age gap between Don and Sarah. They’d both been born in 1960 and had gone through life in lockstep. They’d both been twenty-seven when they’d gotten married; thirty-two when Carl, their first child, had been born; and forty-eight when—

As Don stood, looking at Sarah, the moment came back to him, and he shook his head in amazement. It had been front-page news, back when there were front pages, all over the world. On March first, 2009, a radio message had been received from a planet orbiting the star Sigma Draconis.

The world had puzzled over the message for months, trying to make sense of what the aliens had said. And then, finally, Sarah Halifax herself had figured out what they were getting at, and it was she who had led the team composing the official reply that had been sent on the one-year anniversary of the receipt of the original signal.

The public had initially been hungry for more news, but Sigma Draconis was 18.8 light-years from Earth, meaning the reply wouldn’t reach there until 2028, and any response the Dracons might make couldn’t have gotten here until October 2047 at the earliest.

And a few TV shows and webcasts had dutifully done little pieces last fall noting that a response could be received “any day now.” But none was. Not in October, not in November, not in December, not in January, not…

Not until right now.

No sooner had Sarah gotten off the phone with Lenore than it rang again. The call, as she revealed in a stage whisper while holding her hand over the mouthpiece, was from CNN. Don remembered the pandemonium the last time, when she had figured out the purpose of the first message—God, where had the decades gone?

Everyone was now standing or sitting in a semicircle, looking at Sarah. Even the children had recognized that something major was going on, although they had no idea what.

“No,” Sarah was saying. “No, I have no comment. No, you can’t. It’s my anniversary today. I’m not going to let it be ruined by strangers in the house. What? No, no. Look, I really have to go. All right, then. All right, then. Yes, yes. Good-bye.” She pushed the button that terminated the call, then looked up at Don, and lifted her frail shoulders a bit. “Sorry for all the bother,” she said. “It’s—”

The phone rang again, an electronic bleeping that Don disliked at the best of times.

Carl, taking command, took the hand-set from his mother and flicked off the ringer.

“They can leave a message if they like.”

Sarah frowned. “But what if somebody needs help?”

Carl spread his arms. “Your whole family is here. Who else would call for help?

Relax, Mom. Let’s enjoy the rest of the party.”

Don looked around the room. Carl had been sixteen when his mother had been briefly famous, but Emily had been just ten, and hadn’t really understood what had been going on. She was staring at Sarah with astonishment on her narrow face.

Phones in the other rooms were ringing, but they were easy enough to ignore. “So,” he said, “did—what was her name? Lenore? Did she say anything about the message’s content?”

Sarah shook her head. “No. Just that it was definitely from Sigma Draconis, and seems to begin, at least, with the same symbol set used last time.”

Angela said, “Aren’t you dying to know what the reply says?”

Sarah reached out her arms in a way that said “help me up.” Carl stepped forward and did just that, gently bringing his mother to her feet. “Sure, I’d like to know,” she said. “But it’s still coming in.” She looked at her daughter-in-law. “So let’s get started making dinner.”

The kids and grandkids left around 9:00 p.m. Carl, Angela, and Emily had done all the work cleaning up after dinner, and so Don and Sarah simply sat on the living-room couch, enjoying the restored calm. Emily had gone around at one point, shutting off all the other ringers on the phones, and they were still off. But the answering machine’s digital display kept changing every few minutes. Don was reminded of another old joke, this one from his teenage years, about the guy who liked to follow Elizabeth Taylor to McDonald’s so he could watch the numbers change. Those signs had been stuck at “Over 99 Billion Served” for decades, but he remembered the hoopla when they’d all finally been replaced with new ones that read, “Over 1 Trillion Served.”

Sometimes it was better to just stop counting, he thought—especially when it’s a counting down instead of a counting up. They’d both made it to eighty-seven, and to sixty years together. But they surely wouldn’t be around for a seventieth anniversary; that just wasn’t in the cards. In fact…

In fact, he was surprised they’d lived this long, but maybe they’d been holding on, striving to reach the diamond milestone.

All his life, he’d read about people who died just days after their eightieth, ninetieth, or hundredth birthdays. They’d clung to life, literally by the force of their wills, until the big day had been reached, and then they’d just let go.

Don had turned eighty-seven three months ago, and Sarah had done so five months before that. That hadn’t been what they’d been holding on for. But a sixtieth wedding anniversary! How rare that was!

He would have liked to put his arm around Sarah’s shoulders as they sat side by side on the couch, but it pained him to rotate his own shoulder that much, and—

And then it hit him. Maybe she hadn’t been hanging on for their anniversary. Maybe what had really kept her going all this time was waiting to see what reply the Dracons would send. He wished contact had been made with a star thirty or forty light-years away, instead of just nineteen. He wanted her to keep holding on. He didn’t know what he’d do if she let go, and—

And he’d read that news story, too, dozens of times over the years: the husband who dies only days after his wife; the wife who finally seems to give up and let go shortly after hubby passes away.

Don knew a day like today called for some comment, but when he opened his mouth, what came out were just two words, that, he guessed, summarized it all:

“Sixty years.”

She nodded. “A long time.”

He was quiet for a while, then: “Thank you.”

She turned her head to look at him. “For what?”

“For—” He lifted his eyebrows and raised his shoulders a bit as he sought an answer. And then, finally, he said, very softly, “Everything.”

Next to them, on the little table beside the couch, the counter on the answering machine tallied up another call. “I wonder what the aliens’ reply says,” Don said. “I hope it’s not just one of those damn autoresponders. ‘I’m sorry, but I’ll be away from the planet for the next million years.’ ” Sarah laughed, and Don went on. ” ‘If you need immediate assistance, please contact my assistant Zagdorf at…’ ”

“You are a supremely silly man,” she said, patting the back of his hand.

Though they only had voice phones, Sarah and Don did have a modern answering machine. “Forty-eight calls were received since you last reviewed your messages,” the device’s smooth male voice said the next morning as they sat at the dining-room table. “Of those, thirty-nine left messages. All thirty-nine were for Sarah. Thirty-one were from the media. Rather than presenting them in order of receipt, I suggest you let me prioritize them for you, sorting by audience size. Starting with the TV networks, CNN—”

“What about the calls that weren’t from the media?” Sarah asked.

“The first was from your hairdresser. The second is from the SETI Institute. The third is from the Department of Astronomy and Astrophysics at the University of Toronto. The fourth—”

“Play the one from U of T.”

A squeaky female voice came on. “Good morning, Professor Halifax. This is Lenore again—you know, Lenore Darby. Sorry to be phoning so early, but I thought someone should give you a call. Everyone’s been working on interpreting the message as it comes in—here, over in Mountain View, at the Allen, everywhere—and, well, you’re not going to believe this, Professor Halifax, but we think the message is”—the voice lowered a bit, as if its owner was embarrassed to go on—“encrypted. Not just encoded for transmission, but actually encrypted—you know, scrambled so that it can’t be read without a decryption key.”

Sarah looked at Don, her face astonished. Lenore went on. “I know sending us an encrypted message doesn’t make any sense, but that seems to be what the Dracons have done. The beginning of the message is all math stuff, laid out in that symbol set they used before, and the computer gunks say the math describes a decryption algorithm. And then the rest of the message is total gibberish, presumably because it has indeed been encrypted. Get it? They’ve told us how the message is encrypted, and given us the algorithm to unlock it, but they haven’t given us the decryption key to feed into that algorithm to do the actual unlocking. It’s the craziest thing, and—”

“Pause,” said Sarah. “How long does she go on?”

“Another two minutes, sixteen seconds,” said the machine, and then it added, “She’s quite chatty.”

Sarah shook her head and looked at Don. “Encrypted!” she declared. “That doesn’t make any sense. Why in God’s name would aliens send us a message we can’t read?”

Chapter 3

Sarah fondly remembered Seinfeld, although, sadly, it hadn’t aged well. Still, one of Jerry’s bits of stand-up seemed as true today as it had been half a century ago. When it came to TV, most men were hunters, switching from channel to channel, always on the prowl for something better, while women were nesters, content to settle in with a single program. But today, Sarah found herself scanning constantly; the puzzle of the encrypted message from Sigma Draconis was all over the TV and the web. She caught coverage of oddsmakers paying off winners who’d correctly guessed the day on which a reply would be received, fundamentalists decrying the new signal as a temptation from Satan, and crackpots claiming to have already decrypted the secret transmission.

Of course, she was delighted that there had been a reply, but as she continued to flip channels on the giant monitor above the mantel, she reflected that she was also disappointed that in all the years since they’d detected the first message, no other alien radio source had been found. As Sarah had once said in an interview very much like the ones she was looking at today, it was certainly true that we weren’t alone—but we were still pretty lonely.

Her surfing was interrupted each time someone came up to the front door and rang the bell; an image of whoever it was automatically appeared on the monitor. Mostly it seemed to be reporters; there were still a few journalists who did more than send email, make phone calls, and surf the web.

Those neighbors who had lived here on Betty Ann Drive four decades ago knew Sarah’s claim to fame, but most of the houses had changed hands several times since then. She wondered what her newer neighbors made of the succession of news vans that had pulled into her driveway. Ah, well; at least it wasn’t something to be embarrassed about, like the cop cars that kept showing up at the Kuchma place across the road, and, so far, Sarah had simply ignored all the people who had rung her doorbell, but—

My God.

But she couldn’t ignore this.

The face that had suddenly appeared on the monitor was not human.

“Don!” she called, her voice dry. “Don, come here!”

He had gone into the kitchen to make coffee—decaf, of course; it was all Dr. Bonhoff would let either of them have these days. He shuffled into the living room, wearing a teal cardigan over an untucked red shirt. “What?”

She gestured at the monitor. “My… goodness,” he said softly. “How’d it get here?”

She pointed at the screen. Partially visible behind the strange head was their driveway, which Carl had shoveled before leaving yesterday. An expensive-looking green car was sitting on it. “In that, I guess.”

The doorbell rang once more. She doubted the being pushing the button was actually getting impatient. Rather, she suspected, some dispassionate timer told it to try again.

“Do you want me to let it in?” asked Don, still looking at the picture of the round, blue face, with its unblinking eyes.

“Um, sure,” Sarah said. “I guess.”

She watched as he made his way to the little staircase leading to the entryway, and began the slow pilgrimage down, one painful step at a time. She followed him and stood at the top of the stairs—and noted that one of her grandkids had forgotten a colorful scarf here. By the time Don reached the door, the bell had sounded a third time, which was the maximum number it was programmed to allow. He undid the deadbolt and the chain, and swung the heavy oak door inward, revealing—

It had been weeks since Sarah had seen one in the flesh—not that “in the flesh” was the right phrase.

Standing before them, gleaming in the sunlight, was a robot, one of the very latest models, she guessed; it looked more sophisticated and sleeker than any she’d seen before.

“Hello,” the robot said to Don, in a perfectly normal male voice. It was about five-foot-six: tall enough to function well in the world, but not so tall as to be intimidating. “Is Dr. Sarah Halifax in?”

“I’m Sarah Halifax,” she said. The robot’s head swiveled to look up at her. Sarah suspected it was analyzing both her face and her voice to make sure it was really her.

“Hello, Dr. Halifax,” the robot said. “You haven’t been answering your household phone, so I’ve brought you a replacement. Someone would like to talk to you.” The robot raised its right hand, and in it Sarah could just make out a clamshell datacom.

“And who might that be?” she asked.

The robot tilted its head slightly, giving the impression that it was listening to someone somewhere else. “Cody McGavin,” it said. Sarah felt her heart skip a beat; she wished she’d actually been on the staircase, instead of just above it, so she could have grabbed the banister for support. “Will you take his call?”

Don turned to look at Sarah, his eyes wide, jaw hanging slack.

“Yes,” she said.

The word had come out very softly, but the robot apparently had no trouble hearing her. “May I?” it asked.

Don nodded and stepped aside. The robot came into the entryway, and, to Sarah’s astonishment, she saw it was wearing simple galoshes, which, in a fluid motion, it bent over and removed, exposing blue metal feet. The machine walked across the vestibule, its heels clicking against the old, much-scuffed hardwood there, and it easily went up the first two steps, which was as far as it had to go to be able to proffer the datacom to Sarah. She took it.

“Flip it open,” the robot said helpfully.

She did so, then heard a ringing through the small speaker. She quickly brought the device to her ear.

“Hello, Dr. Halifax,” said a crisp female voice. It was a little hard for Sarah to make out; she wished she knew how to adjust the volume. “Please hold for Mr. McGavin.”

Sarah looked at her husband. She’d repeatedly told him how much she hated people who made her wait like this. It was almost always some self-important jackass who felt his time was more valuable than anyone else’s. But in this case, Sarah supposed, that was actually true. Oh, there might be a few people on Earth who made more per hour than Cody McGavin, but, offhand, she couldn’t name any of them.

As Sarah often said, SETI is the Blanche Dubois of scientific undertakings: it has always depended on the kindness of strangers. Whether it was Microsoft co-founder Paul Allen donating 13.5 million dollars in 2004 to fund an array of radio telescopes, or the hundreds of thousands of private computer users who gave up their spare processing cycles to the SETI@home project, the Search for Extraterrestrial Intelligence had managed to struggle on decade after decade through the largesse of those who believed, first, that we might not be alone, and, later, that it actually mattered that we were not alone.

Cody McGavin had made billions by the time he was forty, developing robotic technology. His proprioceptive sensor webs were behind every sophisticated robot on the planet. Born in 1985, he’d been fascinated by astronomy, science fiction, and space travel all his life. His collection of artifacts from the Apollo program, an endeavor that had come and gone long before he was born, was the largest in the world. And, after the passing of Paul Allen, he’d become by far SETI’s biggest single benefactor.

As soon as Sarah had been put on hold, music started playing. She recognized it as Bach—and got the joke; she was probably one of the few people left alive who would. Years ago, long before the first Draconis signal had been received, during a discussion of what message should be beamed to the stars, Carl Sagan had vetoed the suggestion of Bach, because, he’d said, “That would be bragging.”

In the middle of the concerto, the famous voice came on; McGavin spoke with one of those Boston accents that managed to say “Harvard” with no discernible R sound. “Hello, Dr. Halifax. Sorry to keep you waiting.”

She found her voice cracking in a way that had nothing to do with age. “That’s all right.”

“Well, they did it, didn’t they?” he said, with relish. “They replied.”

“It seems so, sir.” There weren’t many people an eighty-seven-year-old felt inclined to call “sir,” but it had come spontaneously to her lips.

“I knew they would,” said McGavin. “I just knew it. We’ve got us a dialogue going here.”

She smiled. “And now it’s our turn to reply again—once we figure out how to decrypt the message.” Don had been moving across the little entryway, and now was climbing the six stairs. When he was all the way up, she held the datacom at an angle to her face so he could hear McGavin, too. The robot, meanwhile, had taken up a position just inside the front door.

“Exactly, exactly,” said McGavin. “We’ve got to keep the conversation going. And that’s what I’m calling about, Sarah—you don’t mind if I call you Sarah, do you?”

She actually quite liked it when younger people called her by her first name; it made her feel more alive. “Not at all.”

“Sarah, I’ve got a—call it a proposition for you.”

Sarah couldn’t help herself. “My husband is standing right here.”

McGavin chuckled. “A proposal, then.”

“Still here,” said Don.

“Hee hee,” said McGavin. “Let’s call it an offer, then. An offer I don’t think you’ll want to refuse.”

Don used to do a good Brando in his youth. He puffed out his cheeks, frowned, and moved his head as if shaking jowls, but said nothing. Sarah laughed silently and swatted his arm affectionately. “Yes?” she said, into the datacom.

“I’d like to discuss it with you face-to-face. You’re in Toronto, right?”

“Yes.”

“Would you mind coming down here, to Cambridge? I’d have one of my planes bring you down.”

“I… I wouldn’t want to travel without my husband.”

“Of course not; of course not. This affects him, too, in a way. Won’t you both come down?”

“Um, ah, give us a moment to discuss it.”

“Of course,” said McGavin.

She covered the mike and looked at Don with raised eyebrows.

“Back in high school,” he said, “we had to make a list of twenty things we wanted to do before we die. I came across mine a while ago. One of the ones I haven’t checked off yet is ‘Take a ride in a private jet.’ ”

“All right,” she said, into the datacom. “Sure. Why not?”

“Terrific, terrific,” said McGavin. “We’ll have a limo pick you up and take you to Trudeau in the morning, if that’s okay.”

Trudeau was in Montreal; the Toronto airport was Pearson—but Sarah knew what he meant. “Fine, yes.”

“Wonderful. I’ll have my assistant come on, and he’ll look after all the details. We’ll see you in time for lunch tomorrow.”

And the Bach started up again.

Chapter 4

It was ironic, now that Don thought back on it, how often he and Sarah had talked about SETI’s failure prior to its success. He’d come home one day, around—let’s see; they’d been in their mid-forties, so it must have been something like 2005—to find her sitting in their just-bought La-Z-Boy, listening to her iPod. Don could tell she wasn’t playing music; she couldn’t resist tap-ping her fingers or toes whenever she was doing that.

“What are you listening to?” he asked.

“It’s a lecture,” shouted Sarah.

“Oh, really!” he shouted back, grinning.

She took out the little white earbuds, looking sheepish. “Sorry,” she said, in a normal volume. “It’s a lecture Jill did for the Long Now Foundation.”

SETI, Don often thought, was like Hollywood, with its stars. In Tinsel Town, having to use last names marked you as an outsider, and the same was true in Sarah’s circles, where Frank was always Frank Drake, Paul was Paul Shuch, Seth was Seth Shostak, Sarah was indeed Sarah Halifax, and Jill was Jill Tarter.

“The long what?” Don said.

“The Long Now,” repeated Sarah. “They’re a group that tries to encourage long-term thinking, thinking about now as an epoch rather than a point in time. They’re building a giant clock—the Clock of The Long Now—that ticks once a year, chimes once a century, and has a cuckoo that comes out every millennium.”

“Good work if you can get it,” he said. “Say, where are the kids?” Carl had been twelve then; Emily, six.

“Carl’s downstairs watching TV. And I sent Emily to her room for drawing on the wall again.”

He nodded. “So what’s Jill talking about?” He’d never met Jill, although Sarah had.

“Why SETI is, by necessity, a long-term proposition,” Sarah said. “Except she’s skirting the issue.”

“You and she are practically the only SETI researchers who can do that.”

“What? Oh.”

“I’m here all week.”

“Lucky me. Anyway, she doesn’t seem to be getting to the point, which is that SETI is something that must be a multigenerational activity, like building a great cathedral.

It’s a trust, something we hand down to our children, and they hand down to their children.”

“We don’t have a good track record with things like that,” he said, perching now on the La-Z-Boy’s broad, padded arm. “I mean, you know, the environment is something we hold in trust and pass on to Carl and Emily’s generation, too. And look at how little our generation has done to combat global warming.”

She sighed. “I know. But Kyoto’s a step forward.”

“It’ll hardly make a dent.”

“Yeah, well.”

“But, you know,” said Don, “we’re not cut out for this—what did you call it?—this ‘Long Now’ sort of thinking. It’s anti-Darwinian. We’re hardwired against it.”

She sounded surprised. “What?”

“We did something about kin selection on Quirks and Quarks last month; I spent forever editing the interview.” Don was an audio engineer at CBC Radio. “We had Richard Dawkins on again, by satellite through the Beeb. He said that in a competitive situation, you automatically favor your own son over your brother’s son, right? Of course: your son has half your DNA, and your brother’s son only has a quarter of it. But if things got tough between your brother’s son and your cousin, well, you’d favor your brother’s son—that is, your nephew—because your cousin only has an eighth of your DNA.”

“That’s right,” Sarah said. She was scratching his back. It felt very nice.

He went on. “And a second cousin only has one-thirty-second of your DNA. And a second cousin once removed has just one-sixty-fourth of your DNA. Well, when was the last time you heard of somebody volunteering a kidney to save a second cousin once removed? Not only do most people have no clue who their second cousins once removed are, but they also, quite bluntly, couldn’t give a crap what happens to them. They just don’t share enough DNA with them to care.”

“I love it when you talk math,” she teased. Fractions were about as good as Don’s math got.

“And over time,” he said, “the DNA share gets cut down, like cheap coke.” He grinned, delighted by his simile, although she knew full well that the only coke he had experience with came in silver-and-red cans. “You only have to go six generations to get to your own descendants being as distantly related to you as a second cousin once removed—and six generations is less than two centuries.”

“I can name my second cousins once removed. There’s Helena, and Dillon, and—”

“But you’re special. That’s why you are interested in SETI. For the rest of the world, they just don’t have a vested Darwinian interest. Evolution has shaped us so that we don’t care about anything that’s not going to manifest soon, because no close relative of ours will be around then. Jill’s probably tap-dancing around that, because it’s a point she doesn’t want to make: that, for the general public, SETI doesn’t make sense. Hell, didn’t Frank”—whom he’d also never met—“send a signal somewhere thousands of light-years away?”

He looked at Sarah, and saw her nod. “The Arecibo message, sent in 1974. It was aimed at M13, a globular cluster.”

“And how far away is M13?”

“Twenty-five thousand light-years,” she said.

“So it’ll be fifty thousand years before we could get a reply. Who has the patience for something like that? Hell, I got an email today with a PDF attachment, and I thought, geez, I wonder if this thing is going to be worth reading, ’cause, you know, it’s going to take, like, ten whole seconds for the attachment to download and open.

We want instant gratification; we find any delay intolerable. How can SETI fit into a world with that mind-set? Send a message and wait decades or centuries for a reply?” He shook his head. “Who the hell would want to play that game? Who’s got the time for it?”

Chapter 5

As the luxury jet landed, Don Halifax mentally checked off that to-do-list item. The few remaining ones, including “sleep with a supermodel” and “meet the Dalai Lama,” seemed out of the question at this point, not to mention of no current interest.

It was bitterly cold going down the little metal staircase onto the tarmac. The flight attendant helped Don every step of the way, while the pilot helped Sarah. Downside of a private plane: it didn’t use a Jetway. Like so many of the things on Don’s list, this one was turning out to be less wonderful than he’d hoped.

A white limo was waiting for them. The robot driver wore one of those caps that limo drivers are supposed to wear, but nothing else. It did an expert job of getting them to McGavin Robotics, all the while providing a running commentary, in a voice loud enough for them to hear clearly, on the sights and history of the area.

The McGavin Robotics corporate campus consisted of seven sprawling buildings separated by wide snow-covered expanses; the company had lots of ties to the artificial-intelligence lab at nearby MIT. The limo was able to go straight into an underground garage, so Don and Sarah didn’t have to brave the cold again. The robot driver escorted them as they walked slowly over to an immaculate elevator, which brought them up to the lobby. Human beings took over there, taking their coats, making them welcome, and bringing them up another elevator to the fourth floor of the main building.

Cody McGavin’s office was long and narrow, covering one whole side of the building, with windows looking out over the rest of the campus. His desk was made of polished granite, and a matching conference table with a fleet of fancy chairs docked at it was off to the left, while a long, well-stocked bar, with a robot bartender, stretched off in the other direction.

“Sarah Halifax!” said McGavin, rising from his high-backed leather chair.

“Hello, sir,” said Sarah.

McGavin quickly closed the distance between them. “This is an honor,” he said. “A real honor.” He was wearing what Don supposed was the current fashion for executives: a lapelless dark-green sports jacket and a lighter green shirt with a vertical splash of color down the front taking the place of a tie. No one wore ties anymore.

“And this must be your husband,” said McGavin.

“Don Halifax,” said Don. He offered his hand—something he disliked doing these days. Too many younger people squeezed too hard, causing him real pain. But McGavin’s grip was gentle, and released after only a moment.

“A pleasure to meet you, Don. Please, won’t you have a seat?” He gestured back toward his desk and, to Don’s astonishment, two luxurious leather-upholstered chairs were rising up through hatches in the carpeted floor. McGavin helped Sarah across the room, offering her his arm, and got her seated. Don shuffled across the carpet and lowered himself into the remaining chair, which seemed solidly anchored now.

“Coffee?” said McGavin. “A drink?”

“Just water,” said Sarah. “Please.”

“The same,” said Don.

The rich man nodded at the robot behind the bar, and the machine set about filling glasses. McGavin perched his bottom on the edge of the granite desk and faced Don and Sarah. He was not a particularly good-looking man, thought Don. He had doughy features and a small, receding chin that made his already large forehead seem even bigger. Still, he’d doubtless had some cosmetic work done. Don knew he was sixty-something, but he didn’t look a day over twenty-five.

The robot was suddenly there, handing Don a beautiful crystal tumbler full of water, with two ice cubes bobbing in it. The machine handed a similar glass to Sarah, and one to McGavin, and then silently withdrew to behind the bar.

“Now,” said McGavin, “let’s talk turkey. I said I’ve got a”—he paused, and gave the word a special weight, recalling the banter of the day before—“proposition for you.” He was looking at Sarah exclusively, Don noted. “And I do.”

Sarah smiled. “As we used to say about the Very Large Array, I’m all ears.”

McGavin nodded. “The first message we got from Sig Drac was a real poser, until you figured out its purpose. And this one is even more of a puzzle, it seems. Encrypted! Who’d have guessed?”

“It’s baffling,” she agreed.

“That it is,” said McGavin. “That it is. But I’m sure you can help us crack it.”

“I’m no expert in decryption or codes, or things like that,” she said. “My expertise, if I have any, is in exactly the opposite: understanding things that were designed to be read by anyone.”

“Granted, granted. But you had such insight into what the Dracons were getting at last time. And we know how to decrypt the current message. I’m told the aliens made the technique very clear. All we have to do is figure out what the decryption key is, and I suspect your skill is going to be valuable there.”

“You’re very kind,” she said, “but—”

“No, really,” said McGavin. “You were a crucial part of it then, I’m sure you’re going to be a crucial part of it now, and you’ll continue to be so well into the future.”

She blinked. “The future?”

“Yes, yes, the future. We’ve got a dialogue going here, and we need continuity. I’m sure we’ll unlock the current message, and, even if we don’t, we’ll still send a response. And I want you to be around when the reply to that response arrives.”

Don felt his eyes narrowing, but Sarah just laughed. “Don’t be silly. I’ll be dead long before then.”

“Not necessarily,” said McGavin.

“It’ll be thirty-eight years, minimum, before we get a reply to anything we send today,” she said.

“That’s right,” replied McGavin, his tone even.

“And I’d be—well, um…”

“A hundred and twenty-five,” McGavin supplied.

Don had had enough. “Mr. McGavin, don’t be cruel. My wife and I have only a few years left, at best. We both know that.”

Sarah had drained her water glass. The robot silently appeared with a replacement and swapped it for the empty one.

McGavin looked at Don. “The press has had it all wrong, you know, from day one. Most of the SETI community hasn’t understood, either. This isn’t a case of Earth talking to the second planet of the star Sigma Draconis. Planets don’t talk to each other. People do. Some specific person on Sigma Draconis II sent the message, and one specific person on this planet—you, Dr. Sarah Halifax—figured out what he’d asked for, and organized our reply. The rest of us—all the humans here, and anyone else on Sigma Draconis who is curious about what’s being said—have been reading over your shoulders. You’ve got a pen pal, Dr. Halifax. It happens that I, not you, pay the postage, but he’s your pen pal.”

Sarah looked at Don, then back at McGavin. She took another sip of her water, perhaps to buy herself a few seconds to think. “That’s an… unusual interpretation,” she said. “Because of the long times between sending messages and receiving replies, SETI is something whole civilizations do, not individuals.”

“No, no, that’s not right at all,” said McGavin. “Look, what are the fundamental tenets of SETI? Certainly one of them is this: almost any race we contact will be more advanced than us. Why? Because, as of this year, we’ve only had radio for a hundred and fifty-three years, which is nothing compared to the fourteen billion years the universe is old. It’s a virtual certainty that anyone we make contact with has been around as a radio-using civilization longer than we have.”

“Yes,” said Sarah, and “So?” added Don.

“So,” said McGavin, “short lifespans are something only technologically unsophisticated races will be subject to. How long after a race develops radio do you think it is before they decode DNA, or whatever their genetic material is? How long before they develop blood transfusions and organ transplantation and tissue cloning? How long before they cure cancer and heart disease, or whatever comparable ailments sloppy evolution has left them prey to? A hundred years? Two hundred? Doubtless no more than three or four, right? Right?”

He looked at Sarah, presumably expecting her to nod. She didn’t, and, after a moment, he went on anyway. “Just as every race we contact almost certainly must have had radio longer than we have, every race we contact will almost certainly have extended their lifespans way beyond whatever paltry handful of years nature originally dealt them.” He spread his arms. “No, it stands to reason: communication between two planets isn’t something one generation starts, another continues, and still another picks up after that. Even with the long time frames imposed by the speed of light, interstellar communication is still almost certainly communication between individuals. And you, Dr. Halifax, are our individual. You already proved, all those years ago, that you know how they think. Nobody else managed that.”

Her voice was soft. “I—I’m happy to be the, um, the public face for our reply to the current message, if you think that’s necessary, but after that…” She lifted her narrow shoulders slightly as if to say the rest was obvious.

“No,” said McGavin. “We need to keep you around for a good long time.”

Sarah was nervous; Don could tell, even if McGavin couldn’t. She lifted her glass and swirled the contents so that the ice cubes clinked together. “What are you going to do? Have me stuffed and put on display ?”

“Goodness, no.”

“Then what?” Don demanded.

“Rejuvenation,” said McGavin.

“Pardon me?” said Sarah.

“Rejuvenation; a rollback. We’ll make you young again. Surely you’ve heard about the process.”

Don had indeed heard about it, and doubtless Sarah had, too. But only a couple of hundred people had undergone the procedure so far, and they’d all been stinking rich.

Sarah reached forward and set her glass down on the granite desktop, next to where McGavin was leaning. Her hand was shaking. “That… that costs a fortune,” she said.

“I have a fortune,” said McGavin simply.

“But… but… I don’t know,” said Sarah. “I’m—I mean, does it work?”

“Look at me,” said McGavin, spreading his arms again. “I’m sixty-two years old, according to my birth certificate. But my cells, my telomeres, my free-radical levels, and every other indicator say I’m twenty-five. And, if anything, I feel younger even than that.”

Don’s jaw must have been hanging open in surprise. “You thought I’d had a facelift, or something like that?” McGavin said, looking at him. “Plastic surgery is like a software patch. It’s a quick, kludgy fix, and it often creates more problems than it solves. But rejuvenation, well, that’s like a code rewrite—it’s a real fix. You don’t just look young again; you are young.” His thin eyebrows climbed his wide forehead. “And that’s what I’m offering you. The full-blown rejuvenation treatment.”

Sarah looked shocked, and it was a moment before she spoke. “But… but this is ridiculous,” she said at last. “Nobody even knows if it really works. I mean, sure, you look younger, maybe you even feel younger, but the treatment has only been available for a short time. No one who’s had it yet has lived appreciably longer than a natural lifespan. There’s no proof that this process really extends your life.”

McGavin made a dismissive gesture. “There have been lots of rollback tests with lab animals. They all became young again, and then aged forward perfectly normally. We’ve seen mice and even prosimians live out their entire lengthened lifespans without difficulty. As for humans, well, except for a few oddball indicators like growth rings in my teeth, my physicians tell me that I’m now physiologically twenty-five, and am aging forward naturally from that point.” He spread his arms. “Believe me, it works. And I’m offering it to you.”

“Mr. McGavin,” Don said, “I really don’t think that—”

“Not without Don,” Sarah said.

“What?” said McGavin and Don simultaneously.

“Not without Don,” Sarah repeated. Her voice had a firmness Don hadn’t heard for years. “I won’t even consider this unless you also offer the same thing to my husband.”

McGavin pushed himself forward until he was standing. He walked behind his desk, turning his back on them, and looked out at his sprawling empire. “This is a very expensive procedure, Sarah.”

“And you’re a very rich man,” she replied.

Don looked at McGavin’s back, more or less silhouetted against the bright sky. At last, McGavin spoke. “I envy you, Don.”

“Why?”

“To have a wife who loves you so much. I understand the two of you have been married for over fifty years.”

“Sixty,” said Don, “as of two days ago.”

“I never…” McGavin began, but then he fell silent.

Don had vague recollections of McGavin’s high-profile divorce, years ago, and a nasty court case to try to invalidate the prenup.

“Sixty years,” McGavin continued, at last. “Such a long time…”

“It hasn’t seemed that way,” said Sarah.

Don could hear McGavin make a noisy intake of breath and then let it out. “All right,” he said, turning around, his head nodding. “All right, I’ll pay for the procedure for both of you.” He walked toward them, but remained standing. “So, do we have a deal?”

Sarah opened her mouth to say something, but Don spoke before she could. “We have to talk about this,” he said.

“So let’s talk,” said McGavin.

“Sarah and I. We have to talk about this alone.”

McGavin seemed momentarily peeved, as though he felt they were looking a gift horse in the mouth. But then he nodded. “All right, take your time.” He paused, and Don thought he was going to say something stupid like, “But not too much time.”

But instead he said, “I’ll have my driver take you over to Pauli’s—finest restaurant in Boston. On me, of course. Talk it over. Let me know what you decide.”

Chapter 6

The robot chauffeur drove Sarah and Don to the restaurant. Don got out of the car first and carefully made his way over to Sarah’s door, helping her up and out, and holding her arm as they crossed the sidewalk and entered.

“Hello,” said the young white woman standing at a small podium inside the door.

“You must be Dr. and Mr. Halifax, no? Welcome to Pauli’s.”

She gave them a hand getting out of their parkas. Fur was back in vogue—the pelts lab-grown, without producing the whole animal—but Sarah and Don were of a generation that had come to frown on fur, and neither could bring themselves to wear any. Their nylon-shelled coats from Mark’s Work Wearhouse, his in navy blue, hers beige, looked decidedly out-of-place on the racks in the coat check.

The woman took Don’s elbow, and Don took Sarah’s, a side-ways conga line shuffling slowly to a large booth near a crackling fireplace.

Pauli’s turned out to be a seafood restaurant, and even though Don loved John Masefield’s poetry, he hated seafood. Ah, well; doubtless the menu would have some chicken or steak.

There were the usual accoutrements of such places: an aquarium of lobsters, fishing nets hanging on the walls, a brass diver’s helmet sitting on an old wooden barrel. But the effect was much more upscale than Red Lobster; here everything looked like valuable antiques rather than garage-sale kitsch.

Once they’d managed to get seated, and the young woman had taken their drink order—two decaf coffees—Don settled back against the soft leather upholstery.

“So,” he said, looking across at his wife, the crags in her face highlighted by the dancing fire-light, “what do you think?”

“It’s an incredible offer.”

“That it is,” he said, frowning. “But…”

He trailed off as the waiter appeared, a tall black man of about fifty, dressed in a tuxedo. He handed a menu printed on parchment-like paper bound in leather covers to Sarah, then gave one to Don. He squinted at it. Although this restaurant doubtless had lots of older patrons—they’d passed several on the way to the table—anyone who dined here regularly probably could afford new eyes, and—

“Hey,” he said, looking up. “There are no prices.”

“Of course not, sir,” said the waiter. He had a Haitian accent. “You are Mr. McGavin’s guests. Please order whatever you wish.”

“Give us a moment,” said Don.

“Absolutely, sir,” said the waiter, and he disappeared.

“What McGavin’s offering is…” started Don, then he trailed off. “It’s—I don’t know—it’s crazy.”

“Crazy,” repeated Sarah, lobbing the word back at him.

“I mean,” he said, “when I was young, I thought I’d live forever, but…”

“But you’d made your peace with the idea that…”

“That I was going to die soon?” he said, lifting his eyebrows. “I’m not afraid of the D-word. And, yes, I guess I had made my peace with that, as much as anyone does. Remember when Ivan Krehmer was in town last fall? My old buddy from back in the day? We had coffee, and, well, we both knew it was the last time we’d ever see or even speak to each other. We talked about our lives, our careers, our kids and grandkids. It was a…” He sought a phrase; found it: “A final accounting.”

She nodded. “So often, these last few years, I’ve thought, ‘Well, that’s the last time I’ll visit this place.’ ” She looked out at the other diners. “It’s not even all been sad. There are plenty of times I’ve thought, ‘Thank God I’ll never have to do that again.’ Getting my passport renewed, some of those medical tests they make you have every five years. Stuff like that.”

He was about to reply when the waiter reappeared. “Have we decided yet?”

Not by a long shot, Don thought.

“We need more time,” Sarah said. The waiter dipped his head respectfully and vanished again.

More time, thought Don. That’s what it was all about, suddenly having more time.

“So, so he’s talking about, what, rejuvenating you thirty-eight years, so you’ll still be around when the next reply is received?”

“Rejuvenating us,” said Sarah, firmly—or, at least, in what he knew was supposed to be a firm tone; the quaver never quite left her voice these days. “And, really, there’s no need to stop at that. That would only take us back to being fifty or so, after all.”

She paused, took a moment to gather her thoughts. “I remember reading about this. They say they can regress you to any point after your body stopped growing. You can’t go back before puberty, and you probably shouldn’t go back much earlier than twenty-five, before wisdom teeth have erupted and the bones of the skull have totally fused.”

“Twenty-five,” said Don, tasting the number, imagining it. “And then you’d age forward again, at the normal rate?”

She nodded. “Which would give us enough time to receive two more replies from…” She lowered her voice, perhaps surprised to find herself adopting McGavin’s term. “From my pen pal.”

He was about to object that Sarah would be over a hundred and sixty by the time two more replies could be received—but, then again, that would only be her chronological age; she’d be just a hundred physically. He shook his head, feeling woozy, disoriented. Just a hundred!

“You seem to know a lot about this,” he said.

She tipped her head to one side. “I read a few of the articles when the procedure was announced. Idle curiosity.”

He narrowed his eyes. “Was that all?”

“Sure. Of course.”

“I’ve never even thought about living to be over a hundred,” he said.

“Of course not. Why would you? The idea of being ancient, withered, worn out, infirm, for years on end—who would fantasize about that? But this is different.”

He looked at her, studying her face in a way he hadn’t for some time. It was an old woman’s face, just as his face, he knew, was that of an old man, with wrinkles, creases, and folds.

It came to him, with a start, that their very first date all those years ago had ended in a restaurant with a fireplace, after he’d dragged her to see the premiere of Star Trek IV: The Voyage Home. He recalled how beautiful her smooth features had looked, how her lustrous brown hair had shone in the dancing light, how he’d wanted to stare at her forever. Age had come up then, too, with Sarah asking how old he was. He’d told her he was twenty-six.

“Hey, me, too!” she’d said, sounding pleased. “When’s your birthday?”

“October fifteenth.”

“Mine was in May.”

“Ah,” he’d replied, a mischievous tone in his voice, “an older woman.”

That had been so very long ago. And to go back to that age! It was madness. “But… but what would you—would we—do with all that time?” he asked.

“Travel,” said Sarah at once. “Garden. Read great books. Take courses.”

“Hmmmph,” said Don.

Sarah nodded, apparently conceding that she hadn’t enticed him. But then she rummaged in her purse and pulled out her datacom, tapped a couple of keys, and handed him the slim device. The screen was showing a picture of little Cassie, wearing a blue dress, her blond hair in pigtails. “Watch our grandchildren grow up,” she said. “Get to play with our great-grandchildren, when they come along.”

He blew out air. To get to attend his grandchildren’s college graduations, to be at their weddings. That was tempting. And to do all that in robust good health, but…

“But do you really want to attend the funerals of your own children?” he said. “Because that’s what this would mean, you know. Oh, I’m sure the procedure will come down in price eventually, but not in time for Carl or Emily to afford it.” He thought about adding, “We might even end up burying our grandchildren,” but found he couldn’t even give voice to that notion.

“Who knows how fast the cost will come down?” Sarah said. “But the idea of having decades more with my kids and grand-kids is very appealing… no matter what happens in the end.”

“Maybe,” he said. “Maybe. I—I’m just…”

She reached across the dark polished wood of the table and touched his hand.

“Scared?”

It wasn’t an accusation from Sarah; it was loving concern. “Yeah, I suppose. A bit.”

“Me, too,” she said. “But we’ll be going through it together.”

He lifted his eyebrows. “Are you sure you could stand to have me around for another few decades?”

“I wouldn’t have it any other way.”

To be young again. It was a heady thought, and, yes, it was scary, too. But it was also, he had to admit, intriguing. He’d never liked taking charity, though. If the procedure had been something they could have even remotely afforded, he might have been more enthusiastic. But even if they sold their house, sold every stock and bond they owned, liquidated all their assets, they couldn’t begin to pay for the treatment for even one of them, let alone for them both. Hell, even Cody McGavin had had to think twice about spending so much money.

This stuff about Sarah being the one and only person who could communicate with the aliens struck Don as silly. But it wasn’t as though the rejuvenation could be taken back; once done, it was done. If it turned out that McGavin was wrong about her being pivotal, they’d still have all those extra decades.

“We’d need money to live on,” he said. “I mean, we didn’t plan for fifty years of retirement.”

“True. I’d ask McGavin to endow a position for me back at U of T, or provide some sort of retainer.”

“And what will our kids think? We’ll be physically younger than them.”

“There is that.”

“And we’ll be doing them out of their inheritance,” he added.

“Which was hardly going to make them rich anyway,” replied Sarah, smiling. “I’m sure they’ll be delighted for us.”

The waiter returned, looking perhaps a bit wary of the possibility that he was going to be rebuffed again. “Have we made up our minds ?”

Don looked over at Sarah. She’d always been beautiful to him. She was beautiful now, she’d been beautiful in her fifties, she’d been beautiful in her twenties. And, as her features shifted in the light of the dancing flames, he could see her face as it had been at those ages—all those stages of life they’d spent together.

“Yes,” said Sarah, smiling at her husband. “Yes, I think we have.”

Don nodded, and turned to the menu. He’d pick something quickly. He did find it disconcerting, though, to see the item descriptions but no accompanying dollar values. Everything has a price, he thought, even if you can’t see it.

Chapter 7

Don and Sarah had had another discussion about SETI, a year before the original Sigma Draconis signal had been detected. They’d been in their late forties then, and Sarah, depressed about the failure to detect any message, had been worried that she’d devoted her life to something pointless.

“Maybe they are out there,” Don had said, while they went for a walk one evening. He’d gotten religious about his weight a few years before, and they now did a half-hour walk every evening during the good weather, and he used a treadmill in the basement in winter. “But maybe they’re just keeping quiet. You know, so as not to contaminate our culture. The Prime Directive, and all that.”

Sarah had shaken her head. “No, no. The aliens have an obligation to let us know they’re there.”

“Why?”

“Because they’d be an existence proof that it’s possible to survive technological adolescence—you know, the period during which you have tools that could destroy your entire species but no mechanism in place yet to prevent them from ever being used. We developed radio in 1895, and we developed nuclear weapons just fifty years later, in 1945. Is it possible for a civilization to survive for centuries, or millennia, once you know how to make nuclear weapons? And if those don’t kill you, rampaging AI or nanotech or genetically engineered weapons might—unless you find some way to survive all that. Well, any civilization whose signals we pick up is almost certainly going to be much older than we are; receiving a signal would tell us that it’s possible to survive.”

“I guess,” Don said. They’d come to where Betty Ann Drive crossed Senlac Road, and they turned right. Senlac had sidewalks, but Betty Ann didn’t.

“For sure,” she replied. “It’s the ultimate in Marshall McLuhan: the medium is the message. Just detecting it, even if we don’t understand it, tells us the most important thing ever.”

He considered that. “You know, we should have Peter de Jager over sometime soon. I haven’t played go in ages; Peter always likes a game.”

She sounded irritated. “What’s Peter got to do with anything?”

“Well, what’s he best remembered for?”

“Y2K,” said Sarah.

“Exactly!” he said. Peter de Jager lived in Brampton, just west of Toronto. He moved in some of the same social circles as the Halifaxes did. Back in 1993, he’d written the seminal article “Doomsday 2000” for ComputerWorld magazine, alerting humanity to the possibility of enormous computer problems when the year 2000 rolled around. Peter spent the next seven years sounding the warning call as loudly as he could. Millions of person-hours and billions of dollars were spent correcting the problem, and when the sun rose on Saturday, January 1, 2000, no disasters occurred: airplanes kept flying, money stored electronically in banks didn’t suddenly disappear, and so on.

But did Peter de Jager get thanked? No. Instead, he was excoriated. He was a charlatan, said some, including Canada’s National Post, in a year-end summation of the events of 2000—and their proof was that nothing had gone wrong.

Don and Sarah were passing Willowdale Middle School now, where Carl was just finishing grade eight. “But what’s Y2K got to do with the aliens not signaling their existence?” she asked.

“Maybe they understand how dangerous it would be for us to know that some races did manage to survive technological adolescence. We got through Y2K because of lots of really hard work by really dedicated people, but once we were through it, we assumed that we would have gotten through it regardless. Surviving into the year 2000 was taken as—what was your phrase?—‘an existence proof’ that such survival had been inevitable. Well, detecting alien races who’ve survived technological adolescence would be taken the same way. Instead of us thinking it was very difficult to survive the stage we’re going through, we’d see it as a Cakewalk. They survived it, so surely we will, too.” Don paused. “Say some alien, from a planet around—well, what’s a nearby sunlike star?”

“Epsilon Indi,” said Sarah.

“Fine, okay. Imagine aliens at Epsilon Indi pick up the television broadcasts from some other nearby star, um…”

“Tau Ceti,” she offered.

“Great. The people at Epsilon Indi pick up TV from Tau Ceti. Not that Tau Ceti was deliberately signaling Epsilon Indi, you understand; they’re just leaking stuff into space. And Epsilon Indi says, hey, these guys have just emerged technologically, and we did that long ago; they must be going through some rough times—maybe the guys on Epsilon Indi can even tell that from the TV signals. And so they say, let’s contact them so they’ll know it’s all going to be okay. And what happens? A few decades later Tau Ceti falls silent. Why?”

“Everybody there got cable?”

“Funny,” said Don. “Funny woman. No, they didn’t all get cable. They just stopped worrying about somehow surviving having the bomb and all that, and now they’re gone, because they got careless. You make that mistake once—you tell a race, hey, look, you can survive, ’cause we did—and that race stops trying to solve its problems. I don’t think you’d ever make that mistake again.”

They’d come to Churchill Avenue, and had turned east, walking by the public school Emily, who was now in grade two, attended. “But they could tell us how they survived, show us the answer,” said Sarah.

“The answer is obvious,” said Don. “You know the least-best-selling diet book of all time? Losing Weight Slowly by Eating Less and Exercising More.”

“Yes, Mr. Atkins.”

He made his tone one of mock umbrage. “Excuse me! Going for a walk here! Besides, I am eating less, and more sensibly, way more sensibly than I was before I started cutting back on carbs. But you want to know what the difference is between me and all the others who lost weight quickly on Atkins, then put it back on as soon as they quit? It’s been four years now, and I haven’t quit—and I’m never going to. That’s the other piece of weight-loss advice no one wants to hear. You can’t diet temporarily; you have to make a permanent lifestyle change. I have, and I’m going to live longer for it. There are no quick fixes for anything.”

He ceased talking as they crossed Claywood, then began speaking again. “No, the answer is obvious. The way to survive is to stop fighting each other, to learn tolerance, and to put an end to the huge disparity between rich and poor, so that some people don’t hate the rest of us so much that they’d do anything, including even killing themselves, to hurt us.”

“But we need a quick fix,” said Sarah. “With terrorists having access to biotech and nuclear weapons, we can’t just wait for everyone to get enlightened. You have to solve the problem of high-tech terrorism really quickly—just as soon as it becomes a problem—or no one survives. Those alien races who have survived must have found a solution.”

“Sure,” said Don. “But even if they did tell us their answer, we wouldn’t like it.”

“Why?”

“Because,” he said, “the solution is that time-honored sci-fi cliche, the hive mind. On Star Trek, the reason the Borg absorb everyone into the Collective, I think, is that it’s the only safe path. You don’t have to worry about terrorists, or mad scientists, if you all think with one mind. Of course, if you do that, you might even lose any notion that there could be other individuals out there. It might never occur to you to even try to contact somebody else, because the whole notion of ‘somebody else’ has become foreign to your way of thinking. That could explain the failure of SETI. And then if you did encounter another form of intelligent life, perhaps by chance, you’d do exactly what the Borg did: absorb it, because that’s the only way you can be sure it’ll never hurt you.”

“Gee, that’s almost more depressing than thinking there are no aliens at all.”

“There’s another solution, too,” said Don. “Absolute totalitarianism. Everyone’s still got free will, but they’re constrained from doing anything with it. Because all it takes is one crazy person and a pile of antimatter, and—kablooie!—the whole stinking planet is gone.”

A car coming toward them beeped its horn twice. He looked up and saw Julie Fein driving by and waving. They waved back.

“That’s not much better than the Borg scenario,” Sarah said. “Even so, it’s so depressing not to have detected anything. I mean, when we first started pointing our radio telescopes at the sky, we thought we’d pick up tons of signals from aliens, and, instead, in all that time—almost fifty years now—not a peep.”

“Well, fifty years isn’t that long,” he said, trying now to console her.

Sarah was looking off into the distance. “No, of course not,” she said. “Just most of a lifetime.”

Chapter 8

Carl, the elder of Don and Sarah’s two children, was known for his theatrics, so Don was grateful that he didn’t spurt coffee all over the table. Still, after swallowing, he managed to exclaim “You’re going to do what?” with vigor worthy of a sitcom. His wife Angela was seated next to him. Percy and Cassie—in full, Perseus and Cassiopeia, and, yes, Grandma had suggested the names—had been dispatched to watch a movie in Carl and Angela’s basement.

“We’re going to be rejuvenated,” repeated Sarah, as if it were the most natural thing in the world.

“But that costs—I don’t know,” said Carl, looking at Angela, as if she should be able to instantly supply the figure. When she didn’t, he said, “That costs billions and billions.”

Don saw his wife smile. People sometimes thought their son had been named for Carl Sagan, but he wasn’t. Rather, he was named for his mother’s father.

“Yes, it does,” said Sarah. “But we’re not paying for it. Cody McGavin is.”

“You know Cody McGavin?” said Angela, her tone the same as it would have been if Sarah had claimed to know the Pope.

“Not until last week. But he knew of me. He funds a lot of SETI research.” She shrugged a little. “One of his causes.”

“And he’s willing to pay to have you rejuvenated?” asked Carl, sounding skeptical.

Sarah nodded. “And your father, too.” She recounted their meeting with McGavin.

Angela stared in open-mouth wonder; she had mostly only known her mother-in-law as a little old lady, not—as the news-sites kept calling her—“the Grand Old Woman of SETI.”

“But, even if it’s all paid for,” said Carl, “no one knows what the long-term effects of—of—what do they call it?”

“A rollback,” said Don.

“Right. No one knows the long-term effects of a rollback.”

“That’s what everyone says about everything new,” said Sarah. “No one knew what the long-term effects of low-carb dieting would be, but look at your father. He’s been on a low-carb diet for forty years now, and it’s kept his weight, cholesterol, blood pressure, and blood sugar all normal.”

Don was embarrassed to have this brought up; he wasn’t sure that Angela knew that he used to be fat. He’d started putting on weight during his Ryerson years, and, by the time he was in his early forties, he’d reached 240 pounds—way too much for his narrow-shouldered five-foot-ten frame. But Atkins had taken it off, and kept it off, he had been a trim 175 for decades. While the others had enjoyed garlic mashed potatoes with their roast beef this evening, he’d had a double helping of green beans.

“Besides,” continued Sarah, “if I don’t do this, nothing else I start today will have any long-term effects—because I won’t be around for the long term. Even if twenty or thirty years down the road this gives me cancer or a heart condition, that’s still twenty or thirty additional years that I wouldn’t have otherwise had.”

Don saw a hint of a frown flicker across his son’s face. Doubtless he’d been thinking about when his mother had cancer once before, back when he’d been nine.

But it was clear he had no comeback for Sarah’s argument. “All right,” he said at last. He looked at Angela, then back at his mother. “All right.” But then he smiled, a smile that Sarah always said looked just like Don’s own, although Don himself couldn’t see it. “But you’ll have to agree to do more babysitting.”

After that, everything happened quickly. Nobody said it out loud, but there was doubtless a feeling that time was of the essence. Left untreated, Sarah—or Don, for that matter, although no one seemed to care about him—might pass away any day now, or end up with a stroke or some other severe neurological damage that the rejuvenation process couldn’t repair.

As Don had learned on the web, a company called Rejuvenex held the key patents for rollback technology, and pretty much could set whatever price they felt would give their stock-holders the best return. Surprisingly, in the almost two years the procedure had been commercially available, fewer than a third of all rollbacks had been for men and women as old as or older than he and Sarah—and over a dozen had been performed on people in their forties, who had presumably panicked at the sight of their first gray hairs and had had a few spare billion lying around.

Don had read that the very first biotech company devoted to trying to reverse human aging had been Michael West’s Geron, founded in 1992. It had been located in Houston, which made sense at the time: its initial venture capital had come from a bunch of rich Texas oilmen eager for the one thing their fortunes couldn’t yet buy.

But oil was so last millennium. Today’s biggest concentration of billionaires was in Chicago, where the nascent cold-fusion industry, spun off from Fermilab, was centered, and so Rejuvenex was based there. Carl had accompanied Don and Sarah on the trip to Chicago. He was still dubious, and wanted to make sure his parents were properly looked after.

Neither Don nor Sarah had ever been to a private hospital before; such things were all but unheard of in Canada. Their country had no private universities, either, for that matter, something Sarah was quite passionate about; both education and health care should be public concerns, she often said. Still, some of their better-off friends had been known to bypass the occasional queues for procedures at Canadian hospitals and had reported back about luxurious facilities that catered to the rich south of the border.

But Rejuvenex’s clients were a breed apart. Not even movie stars (Don’s usual benchmark for superwealth) could afford their process, and the opulence of the Rejuvenex compound was beyond belief. The public areas put the finest hotels to shame; the labs and medical facilities seemed more high-tech than even what Don had seen in the recent science-fiction films his grandson Percy kept showing him.

The rollback procedure started with a full-body scan, cataloging problems that would have to be corrected: damaged joints, partially clogged arteries, and more.

Those that weren’t immediately life-threatening would be addressed in a round of surgeries after the rejuvenation was complete; those that required attention right now were dealt with at once.

Sarah needed a new hip and repairs to both knee joints, plus a full-skeletal calcium infusion; all that would wait until after the rejuvenation. Don, meanwhile, really could use a new kidney—one of his was almost nonfunctional—but once he was rejuvenated, they’d clone one for him from his own cells and swap it in. He’d also need new lenses in his eyes, a new prostate, and on and on; it made him think of the kind of shopping list Dr. Frankenstein used to give Igor.

Using a combination of laparoscopic techniques, nanotech robotic drones injected into their bloodstreams, and traditional scalpel work, the urgent structural repairs were done in nineteen hours of surgery for Sarah and sixteen for Don. It was the sort of tune-up that doctors normally didn’t recommend for people as old as they were, since the stress of the operations could outweigh the benefits, and, indeed, they were told that there had been a few touch-and-go moments while work was done on one of Sarah’s heart valves, but in the end they came through the various surgeries reasonably well.

Just that would have cost a fortune—and Don and Sarah’s provincial health plan didn’t cover elective procedures performed in the States—but it was nothing compared to the actual gene therapies, which required the DNA in each of their bodies’ trillions of somatic cells to be repaired. Lengthening the telomeres was a key part of it, but so much more had to be done: each DNA copy had to be checked for errors that had intruded during previous copying, and when they were found—and there were billions of such errors in an elderly human—they had to be fixed by rewriting the strands nucleotide by nucleotide, a delicate and complex process to perform within living cells. Then free radicals had to be bound up and flushed away, regulatory sequences reset, and on and on, a hundred procedures, each one repairing some form of damage.

When it was done, there was no immediate change in either Don or Sarah’s appearance. But it would come, they were told, bit by bit, over the next few months, a strengthening here, a firming there, the erasing of a line, the regrowth of a muscle.

And so Don, Sarah, and Carl returned to Toronto, with Cody McGavin again picking up the tab; the flights to and from Chicago had been the only times in his life that Don had flown Executive Class. Ironically, because of all the little surgeries and petty medical indignities, he felt much more tired and worn-out than he had prior to beginning all this.

He and Sarah would take twice-daily hormonal infusions for the next several months, and a Rejuvenex doctor would fly up once a week—all part of the service—to check on how their rollbacks were progressing. Don had vague childhood memories of his family’s doctor making the odd house call in the 1960s, but this was a degree of medical attention that seemed almost sinful to his Canadian sensibilities.

For years, he’d avoided looking at himself in the mirror, except in the most perfunctory way while shaving. He hadn’t liked the way he’d looked back when he was fat, and hadn’t liked the way he’d looked recently, either: wrinkled, liver-spotted, tired, old. But now, each morning, he examined his face minutely in the bathroom mirror, and tugged at his skin, looking for signs of new resiliency. He also examined his bald head, checking for new growth. They’d promised him that his hair would come back, and would be the sandy brown of his youth, not the gray of his fifties or the snow white of the fringe that remained in his eighties.

Don had always had a large nose, and it, and his ears, had grown even larger as he’d gotten older; parts made of cartilage continue to get bigger throughout one’s life. Once the rollback was complete, Rejuvenex would trim his nose and ears down to the sizes they’d been when he really had been twenty-five.

Don’s sister Susan, dead these fifteen years now, had also been cursed by the Halifax family schnoz, and, when she’d been eighteen, after begging her parents for years, they’d paid for rhinoplasty.

He remembered the big moment at the clinic, the unwrapping of the bandages after weeks of healing, revealing the new, petite, retrousse handiwork of Dr. Jack Carnaby, whom Toronto Life had dubbed the finest noseman in the city the year before.

He wished there had been some magical moment like that for this, some ah hah! revelation, some sudden return to vim and vigor, some unveiling. But there wasn’t; the process would take weeks of incremental changes, cells dividing and renewing at an accelerated pace, hormone levels shifting, tissues regenerating, enzymes—

My God, he thought. My God. There was new hair, an all-but-invisible peach fuzz spreading up from the snowy fringe, conquering the dome, reclaiming territory once thought irretrievably lost.

“Sarah!” shouted Don, and, for the first time in ages, he realized he was shouting without it hurting his throat. “Sarah!” He ran—yes, he veritably ran—down the stairs to the living room, where she was seated in the La-Z-Boy, staring at the stone-cold fireplace.

“Sarah!” he said, bending his head low. “Look!”

She came out of whatever reverie she’d been lost in, and although with his head tipped he couldn’t see her, he could hear the puzzlement in her voice. “I don’t see anything.”

“All right,” he said, disappointed. “But feel it!”

He felt the cool, loose, wrinkly skin of her fingers touching his scalp, the fingertips tracing tiny paths in the new growth. “My goodness,” she said.

He tilted his head back to a normal position, and he knew he was grinning from ear to ear. He’d borne it stoically when he’d started to go bald around thirty, but, nonetheless, he found himself feeling inordinately pleased at this almost imperceptible return of hair.

“What about you?” he asked, perching now on the wide arm of the couch near the La-Z-Boy. “Any signs yet?”

Sarah shook her head slowly and, he thought, a little sadly. “No,” said his wife. “Nothing yet.”

“Ah, well,” he said, patting her thin arm reassuringly. “I’m sure you’ll see something soon.”

Chapter 9

Sarah would always remember March first, 2009. She had been forty-eight then, a breast-cancer survivor for five years, and a tenured professor at the University of Toronto for ten. She’d been heading down the fourteenth-floor corridor when she heard, just barely, the sound of her office phone ringing. She ran the rest of the way, glad as always to work in a field that never required her to wear heels. Fortunately, she’d already had her key in hand, or she’d never have gotten through the door before the university’s voice-mail system grabbed the call. “Sarah Halifax,” she said into the beige handset.

“Sarah, it’s Don. Have you been listening to the news?”

“Hi, honey. No, I haven’t. Why?”

“There’s a message from Sigma Draconis.”

“What are you talking about?”

“There’s a message,” Don said again, as if Sarah’s difficulty had simply been in hearing the words, “from Sigma Draconis. I’m at work; it’s all over the wire services and the Internet.”

“There can’t be,” she said, nonetheless turning on her computer. “I’d have been informed before any public announcement.”

“There is a message,” he repeated. “They want you on As It Happens tonight.”

“Um, sure. But it’s got to be a hoax. The Declaration of Principles says—”

“NPR’s got Seth Shostak on right now, talking about it. Apparently they picked it up last night, and somebody leaked it.”

Sarah’s computer was still booting. The handful of musical notes that Windows played on starting up issued from the machine’s speakers.

“What does the message say?”

“No one knows. It’s a free-for-all, with everybody, everywhere, scrambling to figure it out.”

She found herself tapping her fingers rapidly on the edge of her desk and muttering at the computer’s slowness. Big icons were filling in on her desktop, and smaller ones were popping up in her system tray.

“Anyway,” said Don, “I’ve got to go. They need me back in the control room. They’ll call you for a pre-interview later today. The message is everywhere on the web, including Slashdot. Bye.”

“Bye.” She put down the phone with her left hand while maneuvering her mouse with her right, and she soon had the message, a vast array of zeros and ones, on screen. Still dubious, she opened three more browser tabs and started searching for information about when and how the message had been received, what was known about it so far, and so on.

There was no mistake. The message was real.

No one was around to hear her speak, but she sagged back in her chair and said the words anyway, words that had been the mantra of SETI researchers since Walter Sullivan had used them as the title of his famous book: “We are not alone…”

“But Proffesor Halifax, isn’t it true that we might never be able to figure out what the aliens are saying?” the host—a woman named Carol Off—had asked back in 2009, during the As It Happens radio interview. “I mean, we share this planet with dolphins, and we can’t tell what they’re saying. How could we possibly understand what someone from another world is trying to say?”

Sarah smiled at Don, who was in the control room on the other side of the window; they’d discussed this before. “First off, there may in fact be no dolphin language, at least not a rich, abstract one like ours. Dolphins have smaller brains relative to their body weight than humans do, and they devote a huge amount of what they do have to echolocation.”

“So we might not have figured out their language because there’s nothing to figure out?” said the host.

“Exactly. Besides, just because we’re from the same planet doesn’t necessarily mean we should have more in common with them than with aliens. We actually have very little in common with dolphins. They don’t even have hands, but the aliens must.”

“Whoa, Professor Halifax. How do you know that?”

“Because they built radio transmitters. They’ve proven they’re a technological species. In fact, they almost certainly live on dry land, again meaning we have more in common with them than with dolphins. You need to be able to harness fire to do metallurgy and all the other things required to make radio. Plus, of course, using radio means understanding mathematics, so they obviously have that in common with us, too.”

“Not all of us are good at math,” said the host, amiably. “But are you saying that, by necessity, whoever sent the message must have a lot in common with the sort of person who was trying to receive it?”

Sarah was quiet for a few seconds, thinking about this. “Well, I—um, yes. Yes, I guess that’s so.”

Dr. Petra Jones was a tall, impeccably dressed black woman who looked to be about thirty—although, with employees of Rejuvenex, one could never be sure, Don supposed. She was strikingly beautiful, with high cheekbones and animated eyes, and hair that she wore in dreadlocks, a style he’d seen come in and out of fashion several times now. She had arrived for her weekly visit to check up on Don and Sarah, as part of a circuit she did visiting Rejuvenex clients in different cities.

Petra sat down in the living room of the house on Betty Ann Drive and crossed her long legs. Opposite her was a window, one of the two on either side of the fireplace.

Outside, the snow had melted; spring was coming. She looked at Sarah, then at Don, then back at Sarah again, and finally, she just said it. “Something has gone wrong.”

“What do you mean?” said Don at once.

But Sarah simply nodded, and her voice was full of sadness. “I’m not regressing, am I?”

He felt his heart skip a beat.

Petra shook her head, and beads woven into her dreadlocks made small clacking sounds. “I am so sorry,” she said, very softly.

“I knew it,” said Sarah. “I- in my bones, I knew it.”

“Why not?” Don demanded. “Why the hell not?”

Petra lifted her shoulders slightly. “That’s the big question. We’ve got a team working on this right now, and—”

“Can it be fixed?” he asked. Please, God, say that it can be fixed.

“We don’t know,” said Petra. “We’ve never encountered anything like this before.” She paused, apparently gathering her thoughts. “We did succeed in lengthening your telomeres, Sarah, but for some reason the new endcap sequences are just being ignored when your chromosomes are being reproduced. Instead of continuing to transcribe all the way up to the end of your DNA, the replicator enzyme is stopping short, at where your chromosome arms used to end.” She paused. “Several of the other biochemical changes we introduced are being rejected, too, and, again, we don’t know why.”

Don was on his feet now. “This is bullshit,” he said. “Your people said they knew what they were doing.”

Petra flinched, but then seemed to find some strength. She had a slight accent to his ears; Georgia, maybe. “Look,” she said, “I’m a doctor; I’m not in PR. We do know more about senescence and programmed cell death than anybody else. But we’ve done fewer than two hundred multidecade rejuvenation procedures on humans at this point.” She spread her arms a bit. “This is still new territory.”

Sarah was looking down at her hands—her swollen-jointed, liver-spotted, translucent-skinned hands, folded in her lap. “I’m going to stay old.” It was a statement, not a question.

Petra closed her eyes. “I am so sorry, Sarah.” But then she made her tone a bit brighter, although it sounded forced to Don. “But some of what we did was beneficial, and none of it seems to have been detrimental. Didn’t you tell me last time I was here that some of your day-to-day physical discomfort is gone?”

Sarah looked at Don, and she squinted, as if trying to make out someone far, far away. He walked over to her and stood next to where she was seated, placing a hand on her bony shoulder. “You must have some idea what caused this,” he said sharply to Petra.

“As I said, we’re still working on that, but…”

“What?” he said.

“Well, it’s just that you had breast cancer, Mrs. Halifax…”

Sarah narrowed her eyes. “Yes. So? It was a long time ago.”

“When we went over your medical history, prior to commencing our procedures, you told us how it was treated. Some chemotherapy. Radiation. Drugs. A mastectomy.”

“Yes.”

“Well, one of our people thinks that it might have something to do with that. Not with the successful treatment, which you told us about. But he wanted to know if there were any unsuccessful treatments you tried before that.”

“Good grief,” said Sarah. “I don’t remember all the details. It was over forty years ago, and I’ve tried to put the whole thing out of my mind.”

“Of course,” said Petra, gently. “Maybe we should speak to the doctors involved.”

“Our GP from back then is long dead,” Don said. “And the oncologist treating Sarah was in her sixties. She must be gone by now, too.”

Petra nodded. “I don’t suppose your old doctors transferred records to your new doctor?”

“Christ, how should we know?” said Don. “When we changed doctors we filled out medical histories, and I’m sure we authorized the handing over of files, but…”

Petra nodded again. “But this was in the era of paper medical records, wasn’t it? Who knows what’s become of them after all these years? Still, the researcher at our facility looking into this uncovered that about that time—early 2000s, right?—there were some interferon-based cancer treatments here in Canada that weren’t ever approved by the FDA in the States; that’s why we didn’t really know about them. They’re long off the market; better drugs came along by 2010. But we’re trying to find a supply of them somewhere, so that we can run some tests. He thinks that if you had such a treatment, it might be what’s caused our process to fail, possibly because it permanently eliminated some crucial commensal viruses.”

“Jesus, you should have screened more carefully,” Don said. “We could sue you.”

Petra rallied a bit and looked up at him defiantly. “Sue us for what? A medical procedure that you didn’t pay for that had no adverse effect?”

“Don, please,” said Sarah. “I don’t want to sue anyone. I don’t…”

She trailed off, but he knew what she’d been about to say: “I don’t want to waste what little time I have left on a lawsuit.” He stroked her shoulder reassuringly. “All right,” he said. “All right. But can’t we try again? Maybe another round of treatments? Another attempt at rolling back?”

“We have been trying again,” said Petra, “with tissue samples taken from your wife. But nothing is working.”

He felt bile climbing his throat. God damn—God damn everyone. Cody McGavin, for bringing this crazy idea into their lives. The people at Rejuvenex. The bloody aliens on Sigma Draconis II. They could all go to hell.

“This is ridiculous,” said Don, shaking his head back and forth. He lifted his hand from Sarah’s shoulder, and then clasped both his hands behind his back and started pacing the length of the narrow living room, the room that had been home to him and his wife, the room his children had first learned to crawl in, the room that held so much history, so many memories—memories that he and Sarah had shared, decade after decade, good times and bad, thick and thin.

He took a deep breath, let it out. “I want you to stop the process for me, then,” he said, his back briefly to the two women.

“Dear, no,” said Sarah. “Don’t do that.”

He turned around and started pacing toward them. “It’s the only thing that makes sense. I never wanted this in the first place, and I sure as hell don’t want it if you’re not getting it, too.”

“But it’s a blessing,” said Sarah. “It’s everything we talked about: seeing our grandchildren grow up; seeing their children. I can’t—I won’t—let you give that up.”

He shook his head. “No. I don’t want it. Not anymore.” He stopped walking, and looked directly at Petra. “Undo it.”

Petra’s brown eyes were wide. “I can’t. We can’t.”

“What do you mean, you can’t?” said Don.

“Your treatment has been done,” Petra said. “Your telomeres are lengthened, your free radicals are flushed, your DNA has been repaired, and on and on. There’s no way to undo it.”

“There must be,” he said.

Petra lifted her shoulders philosophically. “There hasn’t been a lot of research funding for finding ways to shorten the human lifespan.”

“But you must be able to arrest the rejuvenation, no? I mean, right, I understand that I can’t go back to being eighty-seven physically. Okay, fine. I’m—what?—I suppose I look about seventy now, right? Just stop the rollback here.” He pointed his index finger straight down, as if marking a spot. Seventy he could live with; that wouldn’t be so bad, wouldn’t be an insurmountable gulf. Why, old Ivan Krehmer, he was married to a woman fifteen years younger than himself. Offhand, Don couldn’t think of a case in their social circle where the woman was a decade and a half older than the man, but surely these days that was common, too.

“There’s no way to stop it early,” said Petra. “We hard-coded into the gene therapy how far back the rollback will go. It’s inexorable once begun. Each time your cells divide, you’ll get physically younger and more robust until the target is reached.”

“Do another round of gene therapy, then,” Don said. “You know, to countermand—”

“We’ve tried that with lab animals,” Petra said, “just to see what happens.”

“And?”

She shrugged her shoulders. “It kills them. Cell division comes to a complete halt. No, you have to let the rollback play out. Oh, we could cancel the planned follow-up surgeries—fixing your teeth, your knee joints, getting you that new kidney once you’re strong enough to stand going under the knife. But what would be the point of that?”

Don felt his pulse racing. “So I’m still going to end up physically twenty-five?”

Petra nodded. “It’ll take a couple of months for the rejuvenation to finish, but when it does, that’ll be your biological age, and then you’ll start aging forward again from that point, at the normal rate.”

“Jesus,” he said. Twenty-five. With Sarah staying eighty-seven. “Good Jesus Christ.”

Petra was looking shell-shocked, and she was slowly, almost imperceptibly, shaking her head back and forth. “What?” demanded Don.

The doctor looked up, and it seemed to take her eyes a moment to focus. “Sorry,” she said. “I just—well, I just never thought I’d end up having to apologize for giving someone another sixty or seventy years of life.”

Don crouched down next to his seated wife. How excruciating doing that would have been just a short time ago—and yet it gave him no pleasure now to be able to do it with ease. “I am sorry, honey,” he said. “I am so sorry.”

But Sarah was shaking her head. “Don’t be. It’s going to be all right. You’ll see.”

How could it be all right? he wondered. They’d spent their lives in synch, born the same year, growing up with the same events in the background. Both remembered precisely where they were when Neil Armstrong set foot upon the moon during the year they’d each turned nine. Both had been teenagers when Watergate happened; in their twenties when the Berlin Wall fell; in their thirties when the Soviet Union collapsed; in their forties for the first detection of alien life. Even before they’d met, they’d been marching through the stages of life together, jointly aging, and improving, like two bottles of wine of the same vintage.

Don’s head was swimming, and so, it seemed, was his vision. Sarah’s face appeared blurred, the tears in his eyes doing what Rejuvenex’s sorcery couldn’t, erasing her wrinkles, smoothing out her features.

Chapter 10

Like most SETI researchers, Sarah had worked late many nights after that first alien transmission had been received back in 2009. Don had come to see her in her office at the University of Toronto on one of those evenings, after he’d finished his work at the CBC.

“Anybody home?” he’d called out.

Sarah had swung around, smiling, as he came through the door carrying a red-and-white Pizza Hut box. “You’re an angel!” she crowed. “Thank you!”

“Oh,” he said. “Did you want something, as well?”

“Pig! What did you get?”

“A large Pepperoni Lover’s… ’cause, um, I like pepperoni, and we’re lovers…”

“Awww,” said Sarah. She actually preferred mushrooms, but he couldn’t stand them. Coupling that with his dislike for fish had given rise to the little speech she’d listened politely to him give on numerous occasions, a pseudo-justification that he thought was witty for his eating choices: “You should only eat food that’s as evolved as you are. Only warm-blooded animals—mammals and birds—and only photosynthesizing plants.”

“Thanks for coming by,” she said, “but what about the kids?”

“I called Carl, told him to order a pizza for him and Emily. Said he could take some money out of my nightstand.”

“When Donald Halifax parties, everybody parties,” she said, smiling.

He was looking around for somewhere to set the pizza box. She leapt to her feet and moved a globe of the celestial sphere off the top of a filing cabinet, setting it on the floor. He placed the box where the globe had been and opened its lid. She was pleased to see some steam rising. Not too surprising; the Hut was just up on Bloor Street.

“So, how’s it going?” he asked. This wasn’t the first time he’d brought food to her office. He kept a plate, knife, and fork in one of the office cupboards, and he got them now. Sarah, meanwhile, pulled out a piece of pizza, severing the cheesy filaments with her fingers.

“It’s a race,” she said, sitting down in the chair in front of her workstation. “I’m making progress, but who knows how it compares to what everyone else is achieving? I mean, sure, there’s a lot of sharing of notes going on online, but I doubt anyone is revealing everything yet.”

He found the other office chair—a beat-up folding one—and sat next to her. She was used to the way her husband ate pizza, but couldn’t actually say she liked it. The crust wasn’t part of his diet—of course, the greasy Pizza Hut deep-dish crust probably shouldn’t be part of anyone’s diet, although she found it impossible to resist. He got the toppings off with a fork, swirling it in the molten cheese almost as though he were eating spaghetti. He also ate sandwiches a similar way, digging out the fillings with cutlery while leaving the bread behind.

“Anyway, we’d always expected that math would be the universal language,” Sarah continued, “and I guess it is. But the aliens have managed something with it that I wouldn’t have thought possible.”

“Show me,” Don said, moving his chair closer to her workstation.

“First, they establish a pair of symbols that everybody working on this agrees serve as brackets, containing other things. See that sequence there?” She pointed at a series of blocks on her computer screen. “That’s the open bracket, and that one there”—pointing at another place on the screen—“is the closing bracket. Well, I’ve been doing a rough-and-ready transliteration of everything as I go along—you know, rendering it in symbols we use. So, here’s what the first part of the message says.” She flipped to another window. It was displaying this:

“See how clever they are?” said Sarah. “The brackets let us tell at a glance that there’s nothing in the first set. And see what they’re doing? Establishing digits for the numbers zero through nine—the aliens are using base ten, which may mean they’ve got the same number of fingers we have, or it might just mean that they’ve decoded some of our TV, and have seen that that’s how many fingers we’ve got. Oh, and notice that this chart gives us their equals sign, too.”

He got up and helped himself to another slice; when you skipped the crust, you went through pizza awfully quickly.

“Anyway,” she continued, “they immediately give us the basic mathematical operators. Again, I’ve rendered them in familiar notation.” She rotated the wheel on her mouse, and this scrolled into view:

“See what they’ve done here? They’ve established a symbol for ‘question,’ and another for ‘answer.’ And they’ve also established a symbol for a decimal place, and a symbol for repeating indefinitely, which I’ve shown as that ‘and’ thingy.”

“Ampersand,” said Don, helpfully.

She gave him an I-knew-that scowl, and went on. “Next up, they give us a symbol for ‘the relationship between,’ which I’ve shown as a colon, and that lets us get a bunch of other concepts.” She made this appear:

“See?” she said. “We’re getting into judgment calls. Nine is judged to be not just greater than one but much greater than one, and one, in turn, is much less than nine.

Next they give us their symbols for correct and incorrect.” This appeared on screen:

“And then,” said Sarah, “things get really exciting.”

“I can hardly contain myself,” Don said.

She whapped him lightly on the arm, and nibbled at her own piece of pizza before changing the screen. “This came later in the message. Look.”

“See what they’re saying there? I’ve assigned Greek letters to the two new symbols they’re establishing. Can you puzzle out what alpha and beta mean?”

To his credit, he stopped shoveling cheese and pepperoni into his mouth and studied the screen carefully.

“Welllll,” he said at last, “both answer two and answer three are correct, but, um, well, answer three is more correct, right? ’Cause, I mean, they’ve reduced the fraction.”

“Bravo! That’s exactly right! Now, think about that: they’ve just given us a way to express some very powerful concepts.” She touched a key, and the terms alpha and beta were replaced with words:

“That is, they’ve given us a term for distinguishing between an answer that, while technically correct, isn’t preferable from one that is preferable—distinguishing a bad answer from a good one. And, just to drive home the point that they are making that distinction—that these terms should be translated as polar opposites—they give us this.”

Sarah translated. “What is the relationship between ‘bad’ and ‘good’? Why, they’re opposites, just like one and negative one, as we saw before. They’re saying these terms should be treated as actual opposites, in a way that ‘right’ and ‘more right,’ which would have been the other possible way of translating alpha and beta, aren’t.”

“Fascinating,” he said.

She touched her mouse, and a new display appeared. “Now, what about things that aren’t clear-cut? Well, try this. What does gamma mean?”

“Odd numbers?” he said. “Every other number?”

“Look again. There’s no nine.”

“Oh, right. Oh, and, um, hey, there’s that ‘and’ thingy again.”

“Ampersand,” said Sarah, imitating Don’s helpful tone from earlier. He grinned.

“Right,” she said, “but I’ll give you a hint—something I gleaned from other examples. When the ampersand is right up against another digit, it means that digit is repeated forever. But if there’s a space before it—a little gap in the transmission, as there is here—I think it means that this sequence goes on forever.”

“Three, five, seven, eleven, thirteen…”

“I’ll give you another hint. The next number in the sequence would be seventeen.”

“Um, ah…”

“They’re primes,” she said. ” Gamma is their symbol for prime numbers.”

“Ah. But why start with three?”

She was grinning broadly now. “You’ll see. This is the beauty part.” She darted her mouse around. “There’s a little more set theory, which I won’t bore you with, that establishes a symbol for ‘belongs to this set,’ and then we get this…”

“Does five belong to the set of prime numbers—or, more colloquially, the question is ‘Is five a prime number?’ And the answer is yes; indeed, five was one of the sample numbers we used in naming the set ‘prime numbers.’ ”

She made another similar Q A pair appear:

“Is four a prime number?” said Sarah, interpreting. “No.” She rotated her mouse’s wheel again:

“Is three prime? Yup, sure is. And what about two? Ah, well, let’s have a look.”

More mouse movements, and this appeared:

“Huh?”

“My precise reaction,” said Sarah, smiling.

“So what’s delta?” Don said.

“See if you can figure it out. Look at answer one and answer two for a moment.”

He frowned. “Hey, wait. They can’t both be good answers. I mean, two is a prime number, so saying that it isn’t can’t be a good answer.”

She smiled cryptically. “They give exactly the same three answers for the number one,” she said, scrolling the screen.

“Again, that’s gibberish,” he said. “One either is or isn’t prime. And, well, it is, isn’t it? I mean, a prime is a number that’s only evenly divisible by itself or one, right?”

“Is that what they taught you at Humberside Collegiate? We used to define one as a prime; you’ll see it called such in some old math books. But these days, we don’t. Primes are generally thought of as numbers that have precisely two whole-number factors, themselves and one. One has only one whole-number factor, and so isn’t a prime.”

“Seems rather arbitrary,” said Don.

“You’re right. It is a debatable point. One is definitely an odd-ball as primes go. And two—well, it’s not an odd-ball; it’s an even-ball. That is, it’s the only even prime number. You could just as arbitrarily define the set of primes as all odd numbers that have precisely two whole-number factors. If you did it that way, then two isn’t a prime.”

“Ah.”

“See? That’s what they’re conveying. Delta is a symbol that means, I think, ‘It’s a matter of opinion.’ Neither answer is wrong ; it’s just a matter of personal preference, see?”

“That’s fascinating.”

She nodded. “Now, the next part of the message is really interesting. Elsewhere, they established symbols for ‘sender’ and ‘recipient’—or ‘me,’ the person sending the message, and ‘you,’ the person receiving it.”

“Okay.”

“And with those,” said Sarah, “they get down to the nitty gritty. Look at this.” Her display changed:

“See? The question is, what’s the relationship between good and bad. And the response from the sender, who had said previously, when discussing factual matters, that good is the opposite of bad, now says something quite a bit more interesting: good is much greater than bad—a significant philosophical statement.”

“ ‘Does not your sacred book promise that good is stronger than evil?’ ”

Sarah felt her eyes go wide. “You’re quoting the Bible?”

“Um, actually, no. That’s Star Trek. Second season, ‘The Omega Glory.’ ” He shrugged sheepishly. ” ‘Yes, it is written: good shall always destroy evil.’ ”

Sarah shook her head in loving despair. “You’ll be the death of me yet, Donald Halifax.”

Chapter 11

“McGavin Robotics,” said a crisp, efficient female voice. “Office of the president.”

For once, Don wished he did have a picture phone; for all he knew, he was talking to a robot. “I’d like to speak to Cody McGavin, please.”

“Mr. McGavin is unavailable. May I ask who’s calling?”

“Yes. My name is Donald Halifax.”

“May I ask what this is about?”

“I’m the husband of Sarah Halifax.”

“Ah, yes. The SETI researcher, no?”

“That’s right.”

“What can I do for you, Mr. Halifax?”

“I need to talk to Mr. McGavin.”

“As you might imagine, Mr. McGavin’s schedule is very full. Perhaps there’s something I can help you with?”

Don sighed, beginning to get it. “How many layers deep am I?”

“I’m sorry?”

“How many layers between you and McGavin? If I give you a message, and you decide it’s worth passing on, it doesn’t go to McGavin, does it?”

“Not normally, no. I’m the receptionist for the president’s office.”

“And your name is?”

“Ms. Hashimoto.”

“And who do you report to?”

“Mr. Harse, who is the secretary to Mr. McGavin’s secretary.”

“So I have to get through you, then the secretary’s secretary, then the secretary, before I get to McGavin, is that right?”

“We do have to follow procedures, sir. I’m sure you understand that. But of course things can be escalated quickly, if appropriate. Now, if you’ll just tell me what you need…?”

Don took a deep breath, then let it out. “Mr. McGavin paid for my wife and me to undergo rejuvenation treatments—you know, rollbacks. But it hasn’t worked for my wife, only for me. The doctor from Rejuvenex says nothing can be done, but maybe if she had a request directly from Mr. McGavin. Money talks. I know that. If he indicated he was dissatisfied, I’m sure—”

“Mr. McGavin has had a full report on this.”

“Please,” Don said. “Please, my wife… my wife is going to die.”

Silence. His words were probably more brutally honest than the receptionist to the secretary to the secretary to the president was used to hearing.

“I am sorry,” Ms. Hashimoto said with what sounded like genuine regret.

“Please,” he said again. “Surely whatever report he’s seen came from Rejuvenex, and they’ve doubtless put a spin on it. I want him to understand what we—what Sarah—is going through.”

“I’ll let him know you called.”

No, you won’t, he thought, you’ll just pass it on to the next layer. “If I could just talk to Mr. McGavin, just for a minute. I just…” He hadn’t begged for anything for decades—not since…

It hit him, just then. It hit him like a sucker punch to the gut.

Forty-five years ago. The oncology ward at Princess Margaret. Dr. Gottlieb talking about experimental therapies, about things that were new and untested.

And Don begging her to try them on Sarah, to try anything that might save her. The details were lost to time, but he did now recall the interferon treatment, not approved for use in the States. Gottlieb might have agreed to try it because of his begging, his insistent demands that she do everything that might help.

The experimental treatment had failed. But now, four decades on, its lingering effects were blocking another treatment, all—he swallowed hard—because of him.

“Mr. Halifax?” said Ms. Hashimoto. “Are you still there?”

Yes, he thought. Yes, I’m still here. And I’ll still be here for years to come, long after Sarah’s gone. “Yes.”

“I do understand that you’re upset, and, believe me, my heart goes out to you. I’ll flag this double-red. That’s the best I can do. Hopefully someone will get back to you shortly.”

Just as he had all those many years ago, when Sarah had been trying to translate the first Dracon message, Don stopped by from time to time to see how she was faring with decrypting the current one. But instead of working at the university, she was struggling with this one in the study—the upstairs room that had once been Carl’s.

The Dracons’ original message, the one picked up in 2009, had been divided into two parts: a primer, explaining the symbolic language they were using, and the meat of the message—the MOM, as it rapidly came to be known—which used those symbols in baffling ways. But eventually Sarah had figured out the purpose of the MOM, and a reply had been sent.

This second message from the aliens also had two parts. But in this case, the beginning was the explanation of how to decrypt the rest, assuming the right decryption key could be provided, and the rest, well, that was anybody’s guess. Because it was encrypted, not even a single symbol that had been established in the original message was visible in the second part of this one.

“Maybe the aliens are responding to one of the unofficial responses,” Don said, late one evening, leaning against the study’s doorway, hands crossed in front of his chest. “I mean, even before you sent the official reply, didn’t thousands of people send their own unofficial responses to the Dracons?”

Sarah looked ancient, almost ghostly, in the glow from her magphotic monitor, her thin white hair backlit from his perspective. “Yes, they did,” she said.

“So maybe the decryption key is something that was in one of those messages,” he said. “I mean, I know you worked very hard on it, but maybe the Dracons weren’t interested in the official SETI-team response. Whoever they intended to have read their latest message might already have done so.”

Sarah shook her head. “No, no. The current Dracon message is a response to our official reply. I’m sure of it.”

“That might just be wishful thinking,” he said gently.

“No, it’s not. We put a special header at the top of the official reply—a long numeric string, to identify that message. That’s one of the reasons we didn’t post the entire reply we sent on the web. If we had, everyone would have the header, which would have defeated its purpose. The header was like an official letterhead, uniquely identifying the response we sent on behalf of the whole planet. And this reply to our response references that header.”

“You mean it quotes it?” he asked. “But, then, doesn’t everybody have it now? Any Tom, Dick, or Harry could send a new message to the Dracons and have it look official.”

Her wrinkled features shifted in the cold glow as she spoke. “No. The Dracons understood that we were trying to provide a way to distinguish official responses from unofficial ones. They obviously grasped that we didn’t want everyone who managed to detect their latest message to know what the header was. So the Dracons quoted every other digit from it, making clear to us that they were responding to the official reply, but without giving away what had distinguished the official reply in the first place.”

“Well, there’s your answer,” Don said, quite pleased with himself. “The decryption key must be the other digits from the header, the ones the Dracons didn’t echo back.”

Sarah smiled. “First thing we tried. It didn’t work.”

“Oh,” he said. “It was just a thought. Are you coming to bed?”

She looked at the clock. “No, I—” She stopped herself, and Don’s stomach knotted. Perhaps she’d been about to say I don’t have time to waste on sleeping.

“I’m going to struggle with this some more,” she finished. “I’ll be along in a bit. You go ahead.”

Don called McGavin’s office four more times without any luck, but finally his datacom rang. His ring tone was the five notes from a forgotten film called Close Encounters of the Third Kind, the sort of aliens-come-to-Earth story that seemed quaintly passe now. He looked at the caller ID. It said “McGavin, Cody”—not “McGavin Robotics,” but the actual man’s name.

“Hello?” Don said eagerly, as soon as he’d flipped his datacom open.

“Don!” said McGavin. He was somewhere noisy and was shouting. “Sorry to be so long getting back to you.”

“That’s all right, Mr. McGavin. I need to talk to you about Sarah.”

“Yes,” said McGavin, still shouting. “I’m sorry, Don. I’ve been briefed on all this. It’s just awful. How is Sarah holding up?”

“Physically, she’s okay. But it’s tearing us both apart.”

His tone was as gentle as one’s could be when shouting. “I’m sure.”

“I was hoping you could speak to the people at Rejuvenex.”

“I already have, repeatedly and at length. They tell me there’s nothing that can be done.”

“But there must be. I mean, sure, Rejuvenex has tried all the standard things, but there’s got to be a way to make the rollback work for Sarah if you—”

He stopped talking, which was probably just as well. He’d been about to say, “if you just throw enough money at it.” But McGavin wasn’t listening. Don could hear him saying something to someone else; from the sounds of it, he’d placed a fingertip over his datacom’s mike and was talking to a flunky standing beside him. At last McGavin came back on. “They’re working on it, Don, and I’ve told them to spare no expense. But they’re totally stumped.”

“They thought maybe an experimental cancer drug was the culprit.”

“Yes, they told me that. I’ve authorized them to spend whatever is necessary to try to get hold of a supply of it, or to synthesize it from scratch. But the researchers I’ve spoken to think the damage is irreversible.”

“They’ve got to keep trying. They can’t give up.”

“They won’t, Don. Believe me, this is a huge problem for them. It’s going to affect their stock price, if word gets out, unless they can find a solution.”

“If you hear anything,” Don said, “please, let me know at once.”

“Of course,” said McGavin. “But…”

But don’t have unrealistic hopes ; that was the implicit comment. McGavin had probably seen only an executive summary of the longer report Don had now pried out of Rejuvenex, but the bottom line would have been the same: no solution likely in the near future.

“Anyway,” continued McGavin, “if there’s anything Sarah needs to help with the decryption work, or if there’s anything either you or she needs for anything else, just let me know.”

“She needs to be rolled back.”

“I am sorry, Don,” McGavin said. “Look, I’ve got to get on a plane. But we’ll keep in touch, okay?”

Chapter 12

Back in 2009, those who were part of the formal SETI endeavor had set up a newsgroup to share their progress in figuring out what the various parts of that first, original alien radio message said. It was rumored that the Vatican astronomers were working full-time on trying to translate the message, too, as was, supposedly, a team at the Pentagon. Hundreds of thousands of amateurs were taking a crack at it, as well.

Besides the symbolic-math stuff, parts of the original message turned out to be bitmap diagrams; a researcher in Calcutta was the first to realize that. Someone in Tokyo chimed in shortly thereafter, demonstrating that many of the block-graphic diagrams were actually frames in short animated movies. A new symbol in the last frame of each movie was presumably the word to be used henceforth for the concept that had been illustrated: “growth,” “attraction,” and so on.

The message also contained a lot about DNA—and, yes, there was no doubt that that was what it was, for its specific chemical formula was given. Apparently it was also the hereditary molecule on Sigma Draconis II—which immediately revived old debates about panspermia, the notion that life on Earth had begun when microorganisms from outer space had chanced to land here. The Dracons, some said, might be our very distant cousins.

The message also contained a discussion of chromosomes, although it took a biologist—in Beijing, as it happened—to recognize that that’s what was being talked about, since the chromosomes were shown as rings, rather than long strings.

Apparently, Sarah had learned, bacteria had circular chromosomes, and were essentially immortal, being able to divide forever. The innovation of breaking the circle to make shoelace-like chromosomes had led to the development, at least on Earth, of telomeres, the protective endcaps that diminished each time a cell divided, leading to programmed cell death. No one could say whether the senders had ringlike chromosomes themselves, or whether they were just depicting what they guessed to be either the universal ancestral or most-common kind. On Earth, in terms of biomass and number of individual organisms, chromosomal rings outnumbered the shoelace kind by orders of magnitude.

Once that piece of the puzzle was solved, a bunch of people simultaneously posted that the next set of symbols outlined various stages of life: separate gametes, conception, pre-birth growth, birth, post-birth growth, sexual maturity, the end of reproductive capability, old age, and death.

Lots of fascinating stuff, to be sure, but all of it seemed to be prologue, just a language lesson establishing a vocabulary. None of those early bits, except the tantalizing sample phrase that good was much greater than bad, seemed to actually say anything of substance.

But there was lots of message left—the MOM, the meat of the message, a mishmash of symbols and concepts that had been established earlier, each one tagged with several numbers. Nobody could make sense of it.

The breakthrough came on a Sunday evening. At Chez Halifax, Sunday nights were Scrabble nights, when Don and Sarah sat on opposites sides of the dining-room table, the fancy turntable set that Sarah had bought him many Christmases ago between them.

Sarah didn’t like the game nearly as much as Don did, but she played it to make him happy. He, meanwhile, had less fondness for bridge than she did—or, truth be told, for Julie and Howie Fein, who lived up the street—but he dutifully joined Sarah in a game with them once a week.

They were getting near the end of the Scrabble match; fewer than a dozen tiles were left in the drawstring bag. Don, as always, was winning. He’d already managed a bingo—Scrabble-speak for playing all seven of one’s letters in a single turn—making the improbable wanderous by building on his previous de, one of the many two-letter combos that Scrabble accepted as a word but that Sarah, in all of her forty-eight years, had never seen anyone actually use as a word. Don was an expert in what she called Scrabble babble: he’d memorized endless lists of obscure words, without bothering to learn their meanings. She’d given up long ago challenging any string of letters he played. It was always in the Official Scrabble Players Dictionary, even if her trusty Canadian Oxford didn’t have it. Still, it was bad enough when he played something like muzjik, as he had just now, with both a Z and a J, but to get it on a triple-word score, and—

And suddenly Sarah was on her feet.

“What?” said Don, indignant. “It’s a word!”

“It’s not just the symbol, it’s where it appears!” She was heading out of the dining room, through the kitchen, and into the living room.

“What?” he said, getting up to follow her.

“In the message! The part that doesn’t make sense!” She was speaking as she moved. “The rest of the message defines an… an idea-space, and the numbers are coordinates for where the symbols go within it. They’re relating concepts to each other in some sort of three-dimensional array…” She was running down the stairs to the basement, where, back then, the family computer had been kept. He followed.

Sixteen-year-old Carl was seated in front of the bulky CRT monitor, headphones on, playing one of those damned first-person-shooter games that Don so disapproved of. Ten-year-old Emily, meanwhile, was watching Desperate Housewives on TV.

“Carl, I need the computer—”

“In a bit, Mom. I’m at the tenth level—”

“Now!”

It was so rare for Sarah to yell that her son actually did get up, relinquishing the swivel chair. “How do you get out of this damn thing?” Sarah snapped, sitting down.

Carl reached over his mother’s shoulder and did something with the mouse. Don, meanwhile, turned down the volume on the TV, earning him a petulant “Hey!” from Emily.

“It’s an X-Y-Z grid,” Sarah said. She opened Firefox, and accessed one of the countless sites that had the Dracon message online. “I’m sure of it. They’re defining the placement of terms.”

“On a map?” Don said.

“What? No, no, no. Not on a map—in space! It’s like a 3-D page-description language. You know, like Postscript, but for documents that don’t just have height and width but depth as well.” She was pounding rapidly at the keyboard. “If I can just figure out the parameters of the defined volume, and…”

More keystrokes. Don and Carl stood by, watching in rapt attention. “Damn!” said Sarah. “It’s not a cube… that’d be too easy. A rectangular prism then. But what are the dimensions?”

The mouse pointer was darting about the screen like a rocket piloted by a mad scientist. “Well,” she said, clearly just talking to herself now, “if they’re not integers, they might be square roots…”

“Daddy…?”

He turned around. Emily was looking up at him with wide eyes. “Yes, sweetheart?”

“What’s Mommy doing?”

He glanced back. Sarah had a graphing program running; he suspected she was now glad they’d sprung for the high-end video card that Carl had begged for so he could play his games.

“I think,” Don said, turning back to his daughter, “that she’s making history.”