The Trinity Paradox

7 Los Alamos August 1943

Taking a brisk walk in the mountain air before breakfast made Elizabeth forget about many things. Cool morning wind rushed through the aspen trees; watercolored light splashed off the mesas and the Jemez mountains in the distance. It reminded her of why she had come back to New Mexico, leaving Berkeley and the California fast lane behind.

She hated stepping inside the Project cafeteria for its semblance of breakfast. Cigarette smoke hung like fog in the air from packs of Lucky Strike Greens, the only brand available at the PX. The meal consisted of greasy eggs and bacon, potatoes fried in lard: a year’s supply of cholesterol every morning. It turned her stomach. She found no fresh fruit. Occasionally she managed to secure a bowl of sticky oatmeal or grits.

All these brilliant scientists didn’t know the first thing about keeping themselves healthy and eating right. None of that stuff had been discovered yet—they hadn’t even learned about the connection between cigarettes and lung cancer until the 1950s, after those experiments with dogs hooked up to smoking machines.

She might be looked upon as “queer”—and how even that word had changed!—in her other thoughts and actions as well. She was still trying to learn how to wear a dress again, and how to act around men. After a lifetime of treating her male companions as equals, she felt flustered when the Army men scrambled to open doors for her, or offered her cigarettes, or grinned at her like Howdy Doody every time she passed them on the dusty streets. I’m not a princess, for Christ’s sake!

Mrs. Canapelli kept encouraging her to wear makeup, to do her nails with the rest of the women, to apply garish lipstick so that she left a bright red arc on the coffee cup each time she took a drink. “But you look so plain, dear!” Mrs. Canapelli said as Elizabeth left in the morning, before the other ladies marched over to breakfast. “Don’t you want the young men to notice you?”

“I’ll do just fine,” she said. “And besides, I’m still grieving for Jeff.” After two months, Elizabeth thought. Two months!

“I understand, dear,” Mrs. Canapelli said, and patted her wrist. “Fresh coffee?”

“Thank you.” Elizabeth accepted the cup. Her morning walk provided an easy way to avoid invitations from the other “girls” to join them. They considered her aloof and grumpy; she considered them boring gossips.

Mrs. Canapelli followed Elizabeth to the back porch of the wooden dorm. Elizabeth sipped her coffee; she had gotten accustomed to the odd taste of coffee beans blended with chicory to help with rationing.

The back porch gave a panoramic view of the Sandia peaks. Elizabeth felt she could reach out and touch the desert sprawling below her. “I really appreciate all you’ve done for me. This payday I’ll make up the rest of the money you loaned me on my first night.”

“No hurry, dear. I remember what I went through myself right after Ronald died. Besides, you should never try to pay people back—pay them forward by helping the next person in trouble.”

“Thanks.” Elizabeth smiled as Mrs. Canapelli turned back toward the dorm kitchen. It was really a sign of simpler days, to be so trusting and helpful to anyone with a little bad luck.

Elizabeth had about fifteen minutes until she needed to head out; she could not tell for certain, since she kept her digital watch—sorely out of place in 1943—packed away.

She sat back against the rough outer wall. She felt comfortable here, enjoying the morning. But behind her comfort nagged a feeling that she had begun to stagnate. She couldn’t keep telling herself that this was merely a delusion. And what did it matter if this was just a delusion, if it never ended?

Two months. She had been following the news, trying to assemble the pieces of World War II—and she had to stop thinking of it by that name too, since no one yet called it a “world war.” Mussolini had been overthrown in Italy; the Allies were heavily bombing Germany, Italy, and the Pacific; and the fighting in the Solomon Islands seemed to go on forever. And here she felt so isolated from the rest of the world.

Joining Johnny von Neumann’s calculational group had come naturally enough. Elizabeth didn’t mind the work, though she found it mostly repetitious: add, multiply, subtract, or divide a number that was given to her from the woman beside her. If she got lucky, she might be required to look up the logarithm, or even an exponential. Oh boy! She rarely saw enough of the entire problem to determine what the model was supposed to show, even when the physicists explained it before the calculation.

She wished she had brought along her simplest calculator. She wondered how the Los Alamos scientists could ever overcome the theoretical difficulties of modeling an atomic blast if no one had invented a computer yet.

Von Neumann himself would do that sometime later.

But for the most part, the work was straightforward. Elizabeth had no trouble fitting in and doing her job—and that worried her. She enjoyed her life here. She enjoyed sitting with Graham Fox in the late afternoons, chatting or just relaxing in silence; he had never made a move on her, to her relief. Jeff still burned too close in front of her mind. But she and Fox had enough in common to hold fascinating conversations. He seemed too shy to express any romantic intentions.

Other times, on her Sundays off, she would go hiking by herself throughout the mesas and exploring the areas where she had never been allowed to go in her old life. Mrs. Canapelli disapproved of her going out alone, but Elizabeth ignored her.

With the exception of the Army grunts and some of the civilian workers, the Project people were all above aver age, both in intelligence and in the things that they did. Solving the problems of the universe gave them a passion in their lives, led them to push forward with the need to discover something new, because so much was left to be discovered. It was very different from her own physicist raining, where the all-knowing professors had basically told her How It Was, with no room left for questions, only a bit of fine tuning.

She found the change refreshing, back to the sense of wonder she herself had felt when choosing science in the first place. She might have been able to forget about what was going to happen with the bomb and enjoy herself here. The frantic pace of developing the Gadget brought the men together in a team more intense than any research group before or since. These people were not competing for a Nobel Prize, or even a first publication—they were trying to win a war.

She knew it would be extremely easy for her to be swept up in the group, drift along with the flow of the research; to forget about where she had been and what personal convictions had driven her here, since she had no hope of getting back to her own time. In the past month she had been thinking less and less about Jeff.

And worst of all, she—Elizabeth Devane!—was contributing to the effort. She already knew how everything would escalate, letting the sleeping dog grow more vicious year after year; how the public would become immune to common sense; how it would all lead to her own desperate actions at the MCG site, and how it would cause Jeff’s death.

Below her she heard the cantering of a single horse. Elizabeth stood, holding her warm coffee cup, and looked down the slope to see a rider come up the path. He rode an Appaloosa, guiding it up the side of the hill to a high point on the mesa where he could look back on the settlement of Los Alamos. Elizabeth saw his thin body, gangling arms, and hawkish nose. The man turned, flashed a smile at her, and waved.

As he climbed, she watched his back, the faded red-flannel shirt he wore in the cool morning. When he stopped the horse and turned it, the man was silhouetted by the rising sun. His black outline looked like a scarecrow. He looked hauntingly familiar.

“Oppie’s out for a morning ride again,” Mrs. Canapelli said beside her. Elizabeth had not heard her return to the porch. “He must be thinking of something pretty important.”

Oppie. Oppenheimer—J. Robert Oppenheimer, the mastermind behind the entire atomic bomb project. In a flash Elizabeth remembered where she had seen him before: in footage of the original nuclear test, Trinity. In the light of the dying atomic blast, Oppenheimer had quoted from the Bhagavad Gita, a book of Hindu spiritual poetry—”Now I am become death, the shatterer of worlds.” The expression on his face, the light behind his dark and too-intense eyes, had made him look like the most evil of all mad scientists.

Shatterer of worlds. She thought of the wreckage of Nagasaki and Hiroshima, the shadows of burned bodies cast on brick walls. She thought of Jeff lying dead with fused legs at a time twenty years before he was supposed to be born.

Oppenheimer spurred his horse into motion. At a gallop, they sped over the rise and down the trail into the trees.

“Shouldn’t you be getting off to work, Betsy?” Mrs. Canapelli asked.

Elizabeth finished her cold coffee and handed the cup to Mrs. Canapelli. She needed to get to her work assignment, but she felt more worried about what she would do in the long term.

John von Neumann stood tight-lipped at the front of the room. He had left all the windows closed because of the blowing dust from the streets. Metal fans clicked on empty desks around the room. The scientist with “The Problem Of The Day” paced just outside the door. Elizabeth couldn’t make out who he was.

Thirty women, most of them younger than she by at least five years, waited at their desks for the morning instructions. They were arranged in five rows of six columns. Each desk sat a precise two feet from its neighboring desk, close enough so that when one woman finished her calculation, she would have no trouble handing her answer to the next woman in the queue.

The simplicity of it all impressed Elizabeth. The whole process reminded her of a computer program—each woman would execute one line of the program, either by adding several numbers or performing some other mathematical operation, then hand off her answer to the next woman in line. The solution zigzagged around the room until the last woman tallied the final result.

Once every woman had been briefed on the precise operation she was expected to perform, von Neumann would start off the process by handing the first woman a number written on a sheet of paper. He would continue to hand numbers to the first person in line, taking up all morning and afternoon.

Most of the times the numbers were different, but often Elizabeth could remember identical numbers coming down the pipe. In his brittle Hungarian accent, von Neumann had explained that this was to double-check the accuracy of their calculations. He strode among the desks, looking down at them with his sad, dark eyes, like a Napoleonic schoolteacher.

Before each morning’s session, one of the working scientists would give a short tutorial on what the women were calculating. Elizabeth looked forward to the lectures, eager to learn more about what paths the Los Alamos scientists were taking to design the Gadget and how far along they had come. At first she thought she would be amused at the relative naiveté of the old methods, but she quickly learned that the sophistication was high. Since no one could rely on supercomputers to check models, the Manhattan Project scientists displayed an uncanny intuitive feel for the pertinent physics.

Once the calculations room quieted down, von Neumann cleared his throat. His voice was rich and exotic, with an accent that made him sound like Bela Lugosi in Dracula. “Today’s problem will be covered by Professor Feynman. Dick?”

Elizabeth slid down in her chair as Feynman entered the room. The young man’s infectious grin put the room at ease. He seemed to be flirting with everyone at once. Most of the women just wanted to get started.

Feynman picked up a piece of chalk. He flipped the chalk as he walked around the front of the room, tossing it up and down and catching it precisely each time, though he seemed to be paying no attention at all. As he spoke, Feynman met the eyes of his audience, roving back and forth along the lines of desks.

“We’re trying to overcome a problem of neutron absorption by some of the nonfissile materials. If you can imagine yourself as a little neutron being spit out of a newly formed nucleus”—he crouched low, then sprang high into the air—“and suddenly being grabbed by the wrong type of atom.” He landed on the floor and put his hands around his neck, gasping and choking. “Well, we’re trying to prevent that.”

He released his hands from his neck and spread them wide. “Today you ladies are going to calculate what we call absorption probabilities. Most of the absorption is defined randomly, and the whole process is called the Monte Carlo method—Monte Carlo because it’s based on that famous casino city located in Morocco.

“Anyway, you can look at this calculation as trying to see how many neutrons can survive being absorbed by the wrong material—like when you ladies first got here and fought off the Army types to keep yourselves available for a decent scientist, who would make a much better husband.”

Some of the ladies laughed weakly. Elizabeth did her best to ignore it. Feynman didn’t even know where Monte Carlo was.

“Now these particular calculations are going to be used in what we’re calling our gun experiment. Basically, we want to shoot two blobs of uranium-235 at each other, and we think if we can do it fast enough, then the one resulting hunk will be at critical mass—and that’s what will make our Gadget work. So, what you ladies are doing is very critical.” Feynman grimaced at his own pun, but Elizabeth didn’t think any of the other women understood it. “If the answers look good, we’ll try a small experiment with depleted uranium to get the mechanics down.”

None of the other people seemed to care or understand what the egghead du jour was talking about. Elizabeth listened to everything.

“All right, ladies,” Feynman continued. “The numbers I’ll be giving you correspond to initial neutron velocities and material temperatures. Get ready, and have fun. I’ll ring the bell every ninety seconds to let you know when to transfer your result—that should give you plenty of time to check your calculations.”

At the bell, Elizabeth knew that she had another ten minutes before the first number would work its way through the chain of calculations to reach her position in the string of workers. She kept her eyes averted from Feynman.

She wondered if anyone else might have been desperate enough to steal into the locked offices and change their particular assignments. She dismissed the thought after looking around the room; the rest of the women—they didn’t mind being called “girls”—stared at their work, oblivious to Feynman’s teasing. To the rest of them, this was just assisting the war effort, as much as assembling bomb casings or sewing infantry uniforms. They had no grasp of the big picture.

Feynman looked directly at her for the first time; he winked to show he had known she was there all along. Elizabeth tried to ignore him, but she felt her face grow red.

At any time he could divulge what she had done, that she had falsified her records, that she didn’t belong here inside the fence. And if anyone thought to question her, she would have no answers to give them….

“Elizabeth! Hey, Liz-here!”

“Uh? Oh, sorry.” Elizabeth grabbed the sheet thrust at her. She had not heard the bell ring and had forgotten where she sat. The metal fans continued to make noise, but the air felt too thick for it to stir. Feynman stood at the front of the room watching a miniature hourglass dripping ninety seconds worth of sand. Von Neumann had vanished, probably to work on his own calculations. Elizabeth glanced down at the paper. Written on it was:

She plugged the values into the lengthy equation written on yet another sheet of paper. If only her college physics work had been so simplistic. Seconds later she ran through the algebra and produced another set of values, which she wrote down on a fresh sheet of paper.

She started to set down her pencil and hand the paper to the woman on her right when a thought struck her. What was to keep her from introducing her own errors? To muck things up a little bit. It would take the scientists a while to unravel the problems, to double-check the work. In the meantime, she could be delaying the development of the atomic bomb.

The thought stunned her. Could she change the future? She needed only to stall the work by a few weeks—when Fat Man and Little Boy had been dropped on Hiroshima and Nagasaki, Germany had already fallen and Japan was trying to surrender. A delay of even a handful of days might make the destruction of all those human beings unnecessary. By changing a minus sign or two, she could save a few million lives!

If the atomic bomb could be demonstrated, during peacetime, as part of an exhibition of the potential horrors of nuclear war, then maybe the superpowers would sign immediate agreements to halt, or at least control, their research. The shock that led to the terrible Cold War paranoia would not be nearly so severe.

She could make a difference now. Would she be able to change the future? It couldn’t hurt, no matter what. She need to buy only a few weeks.

The bell rang. Elizabeth tapped her pencil against her lips. The women around her started passing their papers… Elizabeth moved the decimal points on her answers one digit to the right, making each number ten times larger than what she had calculated. She would have to be consistently off from now on, or else the sabotaged answers would stick out too plainly.

Without hesitating, she passed the altered paper to her right. When she accepted the paper from her left, Elizabeth felt confident in what she had to do.

Kirk Hackett felt good about his munitions laboratory, pleased that high-level interest was starting to center on his work. He hadn’t been up on the Hill for more than a few months at the Impact Studies lab when people started coming to him for answers rather than telling him what to do.

After leaving the service five years before as an ordnance man at Sandia Base in Albuquerque, Hackett had continued to serve as a consultant to the Army using his high-explosive expertise. Now that he had been snatched up for the Project and his family relocated to the Hill, Hackett was finally getting his lab into shape. He felt good about working with his superior, George Kistiakowski, the man in charge of all explosives for the Project. Kistiakowski had once used some TNT lifted from the ordnance bunkers to blast clear a ski slope for the Project scientists. Hackett didn’t feel he could get away with anything like that. Not yet.

Lately, more and more scientists had been coming to the lab, taking advantage of his unique facility without understanding what they were doing. It would have been all right if they just asked Hackett to help, asked him to prepare their experiments—but too many of them, tired of spending too much time scribbling theories, wanted to work hands-on with their own schemes. It was like playing to them. Nobody seemed to realize that having a Ph.D. didn’t make one an expert in everything.

Hackett watched the latest intrusion with his arms crossed and a scowl on his face. It was obvious that this crazy Hungarian didn’t have a clue about what he should be doing. But the Hungarian was some sort of bigwig in Project hierarchy, and Hackett had to let him do what he wanted. Hackett had protested to Oppenheimer—he didn’t feel comfortable calling him “Oppie” ye\—but the chief scientist had just smiled around his pipe and told Hackett to be patient. “Some of the scientists need a lot of patience. That one’s a loner, but you couldn’t ask for anyone more brilliant.”

And now, armed with a batch of calculations, the Hungarian scientist waved his arms and insisted that the depleted uranium gun experiment be rearranged, reconfigured to adhere to the latest theoretical results. His theoretical results, checked by some kid named Feynman. So Hackett had reassembled the experiment according to the scientist’s wishes. It didn’t look right, but the models had given the scientist all sorts of numbers to prove everything.

Speaking with a thick accent in his very deep voice, the Hungarian insisted that a steel shield be inserted in front of the gun, just in case the experiment went amiss. Hackett shrugged and complied.

The scientist walked with an exaggerated limp, moving to stand behind the shield, close to the experiment, as Hackett set the fast cameras that would show the depleted uranium spherical pieces flying toward each other, propelled by the detonation into one big lump. Hackett had conducted hundreds of such experiments, all with different explosive charges, so he was not concerned about the Hungarian’s safety—why should this experiment be any different? Didn’t they have their precious calculations to prove everything? The only change this time was in the shape of the uranium lumps that would be shot together. They were fashioned in what the Hungarian called a self-forging configuration.

Hackett yelled at the Hungarian to put on protective goggles. Without a word of acknowledgment, the crazy scientist yanked the lenses over his eyes. With a shrug, Hackett pulled on his own goggles, then started the klaxon, warning people inside the lab of the impending shot. The Hungarian crouched behind the two-inch-thick steel guard. As the countdown continued, Hackett twitched his thumb on the detonator. At zero he pushed the button and an explosion filled the lab. His ears rang.

Nothing unusual.

Standing up, Hackett peered through the smoke. He waved a hand in front of his face and coughed. “Well I’ll be damned.”

A hole some three inches in diameter had been punched through the steel plate. Curved shrapnel looked like flower petals blossoming out from the back side of the metal. Hackett frowned. Usually, the explosive charge left nothing more than a large pit on the front, not even with twice the explosive charge.

“Hey, Doc—you see that?”

When he didn’t get an answer, Hackett scrambled around the still-smoking assembly. On the opposite side of the protective plate, the Hungarian physicist lay on his back, thrown halfway across the room from the impact. Blood oozed from his rib cage, seeping into the dry concrete floor.

“Well I’ll be damned.” In his shock, Hackett couldn’t think of anything better to say.

For the first time since Elizabeth had been coming to the calculation group, von Neumann was late. She had been altering her calculations for more than a week now, and she looked forward to the daily work, where she could make her small differences, chipping away at the Manhattan Project.

Early in the morning, Elizabeth thought she had heard alarms from inside the Technical Area, but no one could be sure. The women waited in the room, seated at their desks, for a good fifteen minutes before anybody suggested that someone find out what was happening. One woman opened a window. None of them looked willing to go check until Elizabeth ran out of patience. She strode out of the building.

The Tech Area was clear of people inside its barbed-wire fence, as though everyone had packed up and walked away. Von Neumann’s office was empty. Elizabeth wandered over by Oppenheimer’s office inside the fence—the Project director kept a room both inside and outside of the classified Tech Area so that anyone on the Hill could have access to him. The office was deserted as well, but Elizabeth didn’t think she would have the nerve to talk to Oppenheimer anyway.

Frowning, she stalked to the meeting hall. The scientists usually gathered there for Monday morning colloquia, a tradition Oppenheimer had established so that technical interchange would flourish within the Project. But this was Wednesday, and she had not heard of any meeting being called.

As Elizabeth approached she could hear angry voices coming from the open door. She slowed her pace, stopping outside of the wooden pre-fab building. She could hear Oppenheimer’s cultured voice pleading with someone, “… a week at the most.”

“But surely someone checked the figures! It’s inconceivable that a three order of magnitude error could slip past! Aren’t all the calculations run through twice?”

Oppenheimer, wearily: “And to reiterate, the procedure will be changed, using two separate and independent teams to check the computational group’s results. The fallacy was to allow the same group to check its own work. So please, there is nothing more we can do. In the meantime, Dr. Teller’s family will appreciate your prayers.” A moment of silence followed.

“All right, if there are no further questions, let’s get back to work. I’ll call a town meeting at lunch to inform everyone else. Because he was so well-known, we may have to come up with some sort of false press release. I’ll have to speak to General Groves about it.”

Elizabeth could hear the sound of chairs being pushed across the wooden floor as the scientists rose from their seats. She stepped back, not sure whether to run as men began leaving the meeting hall. No one spoke to her or even acknowledged that they saw her. They walked out, eyes to the ground.

Elizabeth searched the crowd. She spotted Graham Fox coming toward her. He looked sullen in his baggy clothes. He didn’t even smile as he looked at her. Elizabeth reached out and grabbed his arm. “Graham! What’s the matter?”

“Accidents happen. What do they expect?” Fox’s eyes grew wide. “They failed to tell you?”

“What? Tell me what?”

“Edward Teller.” Fox shook his head. “One of the theoretical physicists. You may have seen him—he had a limp, and a Hungarian accent? He… he tried to test one of the new gun schemes, wanted to be the first. Thought he could improve the gun kinematics for a theory he was working on.”

“What are you talking about?”

Fox shook his head. “The photos showed it all. Magnificent high-speed cameras. He created a self-forming fragment—like a bazooka bullet that jets out, only made out of depleted uranium, which is a very dense metal. The jet was able to punch through a protective plate made of solid steel.”

Elizabeth couldn’t say anything for a moment. Teller was one name she recognized—he had been called the Father of the H-bomb, he had co-founded the Lawrence Livermore Lab, and he had been one of the major advocates of the Star Wars defense program, the x-ray laser, Brilliant Pebbles. Elizabeth had fought against everything he had done—but Edward Teller was an idea man, not a hardware jockey.

“But what was a theoretician doing with the experiment?” she asked.

“Feynman’s results got him excited. The possibilities looked better than he expected. He tried to assemble the blasted thing himself.”

Elizabeth took a step back. “But Teller… he isn’t supposed to die.” She recalled the Livermore protest back in 1983, the time she had been arrested. Teller had lived to a very old age. She remembered marching with the other demonstrators, knowing that just inside the fence, old Teller was up in his ivory tower in Building 111, concocting new ways to destroy the world.

He certainly couldn’t die in 1943, before he had made much of a name for himself. That made everything different.

Fox set his mouth. “Oppie tracked the error down to a misplaced decimal point. No one was at fault, it was a mistake anyone could make. But because the group who checked the numbers was the same group that performed the original calculations, the mistake slipped past them a second time.”

Elizabeth could barely contain the conflicting emotions within her. “But what about the rest of the Project?”

“Oh, don’t worry.” Fox glanced up and narrowed his eyes. He looked around and spoke quietly, sounding bitter. “The work goes on. Teller might have been one of our brightest theoreticians, but the bloody Gadget must be built. The show must go on.”

Fox walked away with the rest of the scientists. Elizabeth leaned back against the door of the meeting hall. I’ve really done it, she thought. I’ve changed history.

But now what was going to happen?

She felt caught in a vice—the exhilaration of being able to change things was tempered by the realization that she had killed someone. Through her tampering with numbers, she had caused a fatal mistake. Would the change be for the better, or worse?

So why wasn’t she ecstatic? The man responsible for developing the hydrogen bomb, the very instrument of death that had escalated the arms race, the billion-dollar buildup of weapons, the nuclear weapons research at Livermore, California—now Teller would never be able to accomplish all that. She could consider herself responsible for wiping clean the slate of inhumanity, perhaps giving the future a real future.

Giving Jeff a second chance. The Jeff in this timeline. He wouldn’t have to die to prevent something that never occurred in the first place.

But as she watched the grim-faced scientists slog back to work, she could tell by their expressions that they had no intention of stopping because of an accident, any more than the future Los Alamos would stop the MCG test because of the deaths of some old scientist and a few technicians. Perhaps the Manhattan Project workers were even more determined to succeed.

Elizabeth would always think of Teller in his tall building behind the restricted-area fence, as she and the other members of the Livermore Challenge Group marched up and down with their banners outside the Lawrence Livermore Laboratory, trying to get someone to listen to their pleas.

In her new timeline, the Manhattan Project would continue, even without Edward Teller.

8 Livermore, California April 1983

Actions speak louder than words. Thoreau might have been content to sit at Walden Pond and write about civil disobedience. Elizabeth Devane had always wanted to do something more tangible. She and others in the Livermore Challenge Group felt their conscience was more important than any laws they might be breaking.

On the morning of the scheduled protest, most of her companions in the van sat in silence, lulled toward sleep as the van moved along the interstate. The sun had not yet risen. Though Jeff dozed beside her, leaning against her shoulder, Elizabeth felt too keyed-up to relax. Everything about this day mattered too much. It was her first major blow against the research that had almost lured her away from an acceptable life.

Since joining the Livermore Challenge Group, Elizabeth had done her bit standing on street corners in Berkeley, handing out leaflets to people who didn’t really care. On the other corners up and down Telegraph Avenue other demonstrators were passing out their leaflets too, side by side with people handing out coupons for pizza restaurants. Many of the students were interested, she knew, but they frequently suffered from activism burn-out, with too many causes to fight for and too many organizations asking for donations. Would it be El Salvador this week, or the homeless, or Ethiopian famine relief, or Amnesty International?

But the gigantic Lawrence Livermore National Laboratory was right in their own backyard, less than an hour’s drive from Berkeley. There, within the mile-square fence, scientists developed generation after generation of nuclear weapons, high yield or low yield, multiple warheads, surveillance systems, death-beam lasers, and who knew what else. Elizabeth couldn’t ignore it. She had fled the defense contractors and the nuclear support industry in Los Angeles, but it seemed she couldn’t escape. As soon as she began to pay attention, the pervasiveness of defense work shocked her.

The Livermore Lab was the heart of the problem. Why couldn’t the scientists see that if they stopped creating new weapons, then the Soviets could stop finding ways to counter them, and this whole madness would grind to a halt?

The Livermore Challenge Group was based in Berkeley to disseminate information about the secret work going on at the Lab, and they also conducted regular protests. Easter—typically Good Friday—was the most appropriate time of year for major demonstrations. By their reckoning, this year’s would be the biggest demonstration ever. About time, Elizabeth thought. She had seen—and been guilty of—too much apathy.

Elizabeth, Jeff, and eight other demonstrators had piled in an old Volkswagen bus, riding out over the Oakland hills in the predawn darkness. She stared out the bug-spattered windshield, watching the river of headlights coming in the opposite direction as people streamed toward the San Francisco Bay for work.

The Volkswagen bus was a dull primer-coat gray, but the driver told her it had once carried elaborate paintings and peace signs. “All that stuff is passé now,” he said. “Nobody takes you seriously.”

Unable to sleep well the night before, she and Jeff had held each other, talking, running finger touches along each others’ backs, until finally they made love; exhausted, they managed to get a few hours of sleep before getting up for the demonstration. Elizabeth had gulped several cups of coffee at the headquarters, and she sipped another from the thermos beside the driver.

The other demonstrators had arrived outside the Livermore Lab, parking their vehicles up and down East Avenue or Vasco Road, in open areas by the vineyards. She saw people milling about in the darkness. Someone had a Coleman lantern set on the hood of his pickup truck. Others carried candles, but the breeze kept gusting them out. One woman filled small helium balloons and handed them to anyone who walked by.

Many people had painted their own signs and banners, but some had made extras, looking for volunteers to carry them, stop livermore Auschwitz or work for life, not death or teach peace. A woman in a lavish fur coat looked out of place, but it didn’t seem to bother her. One man in a wheelchair wore a cowboy hat and held a handful of little stick crosses in his lap. Around him milled a dozen or so other protesters with T-shirts that proclaimed them as bay area baptist peacemakers.

The Livermore Challenge Group acted as a rallying point for numerous clubs and organizations—many with wildly different political views, but all of whom had found the Livermore Lab a suitable target. United we stand. We shall overcome.

The businesslike and gentlemanly procedures of the Livermore Challenge Group surprised Elizabeth. She had her preconceptions of what a demonstration would be like, concerned citizens battling the establishment, like a spillover from sixties news clips. But the Livermore Challenge Group had composed a formal, considerate letter to the Director of the Livermore Laboratory, informing him of the date of the demonstration and giving details about how many people were expected to attend, how many had volunteered to commit civil disobedience. This allowed the Laboratory to have adequate security forces on hand and adequate facilities to hold the detainees.

Elizabeth had even seen a bootlegged videotape shown to Lab security guards on How to Arrest a Nuclear Protester, demonstrating proper handholds, procedures, and what not to do. To counter that, the Livermore Challenge Group had also given each volunteer special training in how to get arrested, what to do, what their rights entitled them to. She looked at the yellow armbands worn by some people, designating them as volunteers to be arrested. The armband gave them a certain status among the other protesters.

Elizabeth envied them. She had discussed with Jeff the possibility of volunteering, but he had talked her out of it. Since leaving her nuclear work behind, Elizabeth had jumped into the protest movement headfirst; Jeff told her she was going overboard, that she should wait and maybe get arrested next time, when she could make a rational, cool-headed decision, rather than charging ahead without thinking of the consequences. She had grudgingly agreed.

Full daylight had seeped into the sky as Elizabeth wandered about. The excitement kept building in her. Jeff held her hand, and she could feel the tension in his muscles. The collective emotions here charged the air, tingeing everything with unreality.

Already, roving cameramen for the Lab’s closed-circuit televisions walked among the protesters, chatting. It all seemed very cordial. Reporters from two local TV stations had also showed up with minicams, carrying boom microphones and looking for something interesting to videotape. Dan Fogelberg’s song “Kill the Fire” permeated the camp.

Several people obliged with appropriate theatrics. A bearded man appeared in hiking boots and a white anti-contamination suit made from an old bed sheet. Three people—Elizabeth couldn’t tell if they were men or women—came out, dressed completely in black, their faces painted like skulls. Two held flags high showing the three-bladed radiation symbol obscured by the circle-and-slash universal No sign. The middle figure carried a sign that said you can’t run from radioactive wastes.

Elizabeth got another lukewarm cup of coffee from a community thermos and sipped it as she walked along the chain-link fence. Traffic picked up on East Avenue as people came to work at the Lab, each passing through the main gate as a security guard—no, she corrected herself, they called themselves “protective servicemen”—checked the employees’ badges and waved them ahead to the entrance station.

A few of the banners—we oppose your work, not you!—served to maintain relative goodwill between the employees and the protesters. They didn’t really expect Lab employees to read the banner slogans, turn their cars around, and refuse to come to work. When she had worked at United Atomics, Elizabeth would never have done that herself. She had always ignored the few protesters, thinking that none of it concerned her, that the demonstrators just didn’t understand she wasn’t doing anything wrong. Or so she had thought at the time. She wondered now how she could have been so misled.

“Won’t be long now,” Jeff said. “Are you doing okay?”

Elizabeth saw by her watch that it was seven-thirty. She felt the butterflies in her stomach take flight. “Sure,” she said.

The full complement of Lab security guards lined up, marching out like Nazi storm troopers. Most wore tan uniforms, others dark blue; she didn’t know what the difference meant. Reinforcements from the California Highway Patrol joined them. All had white helmets and transparent race shields. She counted four German shepherd dogs. The female guards all looked extremely tough, as if it were a matter of pride. Elizabeth wondered how much this one demonstration would cost the government, but it didn’t bother her—it was money that couldn’t be spent on nuclear weapons.

Along the fence line people started singing an endless chorus of “Give Peace a Chance.” Looking at the security forces in their crisp uniforms and weapons, and the protesters in a kaleidoscope of jeans and T-shirts, headbands and bright skirts, Elizabeth thought this was a culture clash as much as anything else. Like the sixties all over again? She had missed most of the demonstrations then; she’d been too young.

She felt overwhelmed by the power of all the people gathered together. From the outside it might have looked like chaos, but here, a part of everything, she felt herself to be a vital piece of a very strong machine. They would overcome. It didn’t seem possible they could fail, not when it felt like this. Couldn’t the guards sense it too?

Four demonstrators had used a garden chain to attach themselves to the outer fence, forcing the security guards to find a pair of bolt cutters to remove it and arrest them. But that was merely a diversion.

The first group of people wearing yellow armbands lined up on the corner of East Avenue and Vasco Road, the main intersection near the Lab’s front gate. Others cheered them on. Elizabeth raised her fist. Tears sparkled in her eyes. It seemed such a magnificent sacrifice. Jeff put his arm around her. The first group of seven marched into the street as soon as the light changed. Together they sat down on the pavement.

Elizabeth watched, wondering what it would be like to sit out there, her face level with an approaching car, willing it to stop, willing everything to stop. With the emotional support of the gathered demonstrators, they could do anything.

Security forces moved in on the seven protesters sitting in the road. Working from the left, the group of guards surrounded the first protester, a man in patched jean jacket and a red headband. Six guards blocked him off on all sides, isolating him from the others. The media cameras pushed closer. Cars stopped and began to block the intersection. Elizabeth grabbed Jeff’s hand and pulled him closer so she could see, and hear, and experience what was happening.

One of the security men warned the demonstrator. Another guard timed everything with a watch. After an appropriate period had passed, the officer issued another warning, quoting some California statute. The demonstrator, barely visible between the blockade of security men, sat in silence, refusing to move. Elizabeth clenched her hand, feeling fingernails bite into her palm. Waves of anger and emotion poured from the man on the pavement. It seemed an outrage.

After the third warning, the officer placed the man under arrest. Guards picked him up and removed him from the road, then encircled the second person, repeating the entire procedure. People cheered. The cameras recorded. The first arrestee managed to raise his fist high as the guards carried him off.

Elizabeth watched, but she didn’t really see. Her anger was culminating in this one action. She wondered what had driven these other people to extremes. She had never been arrested before. She had always chosen the safe way, Jeff’s way.

But hadn’t she gotten tired of passing out leaflets, consoling herself by arguing with other activists who already agreed with her anyway? “Once you get arrested, your record is never clear,” Jeff kept saying. “That information will appear every time you apply for a job for the rest of your life.”

She hummed the chorus of “Give Peace a Chance” with the others. The security guards arrested another demonstrator.

The last time she had visited Ted Walblaken in the hospital, he had patted her arm with his clammy hand. “Have a good life,” he said. Somehow it didn’t sound corny to her. He had known he was saying good-bye, that the cancer would take him before long.

United Atomics had denied everything. They had somehow misplaced Ted’s exposure records over his career of working in the processing shop with its lax radiation safety standards. The California Occupational Safety and Health Administration had fined United Atomics, citing them with more than a dozen safety violations. United Atomics had paid the fines, weathered the negative publicity, and considered the slate cleared.

Ted Walblaken had died at the age of forty-six, in a hospital room with his wife and three children at his side.

“If you get arrested, that record will haunt you for the rest of your life,” Jeff had said. But how many lives did it take? It was worth it. She could not sit in silence anymore.

Elizabeth turned to meet Jeff’s eyes. “I’m going,” she said. “Are you coming with me?”

Behind his glasses Jeff turned into a stranger in front of her.’ ‘You can’t! Think about what you’re doing, Elizabeth.”

“I’ve had too much thinking. That’s not enough anymore. “ She pulled her arm, and suddenly Jeff was not holding her hand but was holding her back. She jerked away.

“Fine,” he said. His voice carried scorn, and in that instant everything changed between them.

Elizabeth pushed into the second group to march across the street. Some of them looked surprised at her intrusion, but others smiled and nodded. One old man patted her shoulder. Trying not to stumble, she walked onto the pavement, saw oil stains, an old crushed cigarette butt, a broken bottle at the side of the road. She sat down and faced the traffic. The cars stopped as frustrated employees tried to get past the blockade. Someone a few rows back honked his horn, startling everyone.

The gathered protesters along the fence cheered for her now. She thought of old Ted being among them. She did not look to see if Jeff had remained to watch.

The front car edged closer, pushing the grill close to Elizabeth’s chest. She leaned back, forcing herself not to close her eyes. She could hear the rumble of the engine. Staring at the fish-eyed headlights, she could not see the driver’s face, only the license plate, skier 4. What on earth did that mean?

She could stop everything. She had to do her best.

Elizabeth felt the rough pavement under her skirt. The road remained cold from the morning. She stared straight ahead, focusing on remaining where she was. Only that mattered.

Ranks of guards strode out across the road again. Elizabeth did not look up. She saw only sets of legs in identical tan uniforms and dangling black riot clubs. She heard the officer’s voice droning, and the person next to her was carried off.

The anger, the triumph, the love and support of her companions, pounded on her in waves. She felt that it would lift her up and rescue her, rescue them all, and change the world.

“We request that you leave these premises,” the guard said. “If you choose to remain, we can arrest you. Will you leave voluntarily?”

She realized he was speaking to her. She heard the engine of the car in front of her and smelled the mixture of gasoline and exhaust. In the background she could hear the song begin yet another chorus.

“I can’t just sit in silence anymore,” she muttered.

“This is your second warning.” She hadn’t noticed any time passing at all, but out of the corner of her eye she saw another officer staring at his watch. The first man recited lines from a California statute. Her conscience counted more than any laws. Laws promoting research that led to mass murder were immoral, and she could not be held accountable by them.

“If you choose to remain, you will be arrested. Do you choose to remain?”

“I can’t just sit in silence anymore,” she said again, as if it were a chant. She was doing something. She would make some sort of difference, some sort of statement for everyone to see. Jeff didn’t matter at all anymore.

“You are under arrest.”

She hadn’t even seen the officer’s face. Strong hands grabbed her arms, but she refused to stand, refused to cooperate in any way whatsoever. Every part of her felt numb, but euphoric. Two guards picked her up by the arms in a skillful carry; as time went on and they got tired, no doubt the handling would get rougher. She let her shoes drag on the pavement, making it difficult for them to haul her off. A third guard picked up her legs. Everything felt very careful. Too many cameras were watching.

From the sidelines others cheered and continued to sing. The Bay Area Baptist Peacemakers went into a hymn, which overlapped with the continuing chorus of “Give Peace a Chance.”

In the group with the other arrestees, a woman guard wrapped Elizabeth’s wrists with plastic handcuffs, a thick band like a tie for a garbage bag. The guard’s belt had a clip holding about a hundred sets of cuffs. Elizabeth couldn’t snap out of the restraints; for mass arrests the plastic cuffs were as effective as but much cheaper and simpler than metal handcuffs.

She waited for over an hour as more people came into the detaining area. It still hadn’t sunk in yet. She rode the crest of her feelings. Everyone around her seemed to be in a similar daze.

Processing started without delay, with clerks in guard uniforms filling out the arrest forms and going through the bureaucratic ritual. Some protesters remained militant and gave blatantly false names, false Social Security numbers, false addresses—but Elizabeth thought that was stupid. They had already made their point, and misinformation would only delay their own release. Resisting now harmed no one but themselves.

At last, late in the morning, the arrestees were loaded on buses, then taken to nearby Santa Rita prison. Elizabeth sat uncomfortably in her seat, with the plastic edge of the handcuffs chafing her skin. The bus felt crowded and stifling, filled with the odors of too many sweating and nervous people.

The worst part of all was enduring how badly she had to go to the bathroom after gulping so many cups of coffee….

At the time, back in 1983, Elizabeth felt she had made the supreme sacrifice. She had committed civil disobedience for her cause. She had allowed herself to be arrested for something she believed in, and she hoped her one gesture among all those others would matter for something. She hoped it would be enough.

But it had done nothing. None of it mattered now, as she stood outside the wooden pre-fab buildings in old Los Alamos, watching the scientists go about their work of designing the first atomic bomb, the initial domino in an endless chain of weapons. That first protest at Livermore had set her on a path that brought her back to New Mexico, that brought her out to sabotage the MCG site at night, that resulted in Jeff’s death and threw her back in time.

Now she had a chance to do something much more than protest, something more drastic.

Something that would make a real difference to all of history.

9 Berlin—the Virus House October 1943

The truck pulled up with the last shipment of graphite blocks. Professor Abraham Esau stood in the doorway of the Virus House laboratory, watching it stop in front of the wrong building. Two other technicians ran out in the cold autumn drizzle to direct the driver toward the main bunker. The armed guards on the truck raised their rifles and aimed at the men hurrying toward them; the technicians stopped just in time, waving their arms.

In a way, Esau found it ludicrous, squadrons of guards flanking a graphite truck. Why would any outside saboteur want to steal a shipment of carbon! He’d had an extremely difficult time convincing the German graphite manufacturers—who had never seen more than a minimal war demand for their product—of his need for absolute priority. When orders on his “Plenipotentiary” stationery proved ineffective, Esau had obtained a direct letter from Reich-minister Speer. Finally, things got done properly.

Esau had used Speer’s authorization letter several more times, first to insist on delivery within weeks rather than months, then to force the companies to manufacture graphite with a process that used petroleum coke rather than mineral coke. The new process proved much messier for the manufacturer and cut production in half—but the mineral process always contaminated graphite with boron, the neutron absorber that had ruined Walther Bothe’s initial measurements.

Esau hated it when people, through their own laziness, tried to deceive him. “It cannot be done!” the manufacturers said. But Esau was aware of the petroleum process because some British factories produced ultra-pure graphite for specialized use in electrode tips. He and Graham Fox had required those elements for their experimental work back in Cambridge.

“It will be done,” he muttered to himself outside the Virus House, then pulled up the collar on his jacket and hurried over to the truck.

The driver and the guards worked with Virus House technicians to unload the crates and take them into the bunker building. Esau watched them work. The drizzle could have ruined some of the shipment, but someone had thought to wrap the boxes in waxed paper, which kept everything dry. Other technicians emerged from the bunker, their faces looking comically black from carbon dust.

Esau waited by the truck cab in the shadow of the rain until the workers had finished unloading. “I am Professor Esau. Do you have a receipt for me?” he asked the guard captain.

“Yes, sir.” The guard fumbled inside his wet leather jacket and withdrew a folded set of papers.

Esau took them and removed a fountain pen from his pocket, looking for a flat surface on which to write and finally settling on the wet side of the truck. He scrawled his initials and then carefully printed his full title below. “Now we have everything,” he said to himself.

“Heil Hitler!” the guard said, tucking the papers back inside his pocket.

Esau responded, then walked back toward the bunker. He didn’t listen as the motorcycles started and the truck ground its gears, backing up in the mud and gravel where Heisenberg had been shot two months before.

Inside the bunker, Esau approached the researchers and their assistants. The interior walls had been knocked down by scientists with sledgehammers, leaving only support beams at regular intervals throughout the room. Near the door, Esau stepped around crates filled with ultra-pure graphite bricks, all cut to size for the appropriate lattice spacing.

Much of the floor had been torn up in the center; long wooden planks with protruding nails lay piled against one wall. Construction workers had dug a large pit in the ground, lined it with concrete and then with plates of beryllium metal to reflect back neutrons that tried to spill out of the growing pile.

Down in the pit, three workers had placed a layer of carbon bricks along the bottom. Others passed more of the black, shiny blocks down in a fire-brigade line. Smashed fingers occurred regularly as the workers fumbled with the slippery graphite.

Dr. Kurt Diebner, Esau’s former rival, was one of the men down in the pit doing menial work. Esau smiled, considering it good for the man to get his hands dirty. And dirty he certainly was—his face, his balding head, his thick black glasses, his hands, his neck—everything was covered with shiny black dust that stuck to his sweat, clung to his pores.

All of the scientists from the scattered groups of German nuclear research had been summoned here to share offices in the Virus House. Esau himself had moved away from his precious office in the Federal Building downtown. Now, in the unimpressive barracks, he occupied Werner Heisenberg’s former office. He did that intentionally for its psychological effect, to emphasize who was in charge and what he could do if the other researchers displeased him.

He had assigned Diebner to share an office with Manfred von Ardenne, the man who had convinced the Reichpost Ministry to fund his private nuclear research. Von Ardenne was a pleasant, quiet, but brilliant researcher— probably the only one who could tolerate Diebner’s excessive ego for any length of time.

Diebner and Paul Harteck—the two dynamos behind the Göttingen research group—stuck together in their clique, working on their solo research and keeping their secrets. Or at least they had tried to—Esau had put a stop to it immediately. No longer were they petty factions competing against each other. They were competing against the Americans, who, according to Graham Fox’s message, had already succeeded beyond anything the Germans had accomplished.

The floor in the bunker felt slick from the fine black dust that clung to everything. While the graphite bricks had been cut to proper size, the workers used modified woodworking tools to cut notches for the uranium cubes. Each of the lattice holes had to be customized, because Esau was using all the uranium and uranium oxide he had cobbled together from the scattered experiments of the other research teams.

Uranium metal cubes would be scattered at six-inch intervals in the graphite material, but Carl-Friedrich von Weizsacker’s calculations had shown that this would not be enough to make the reaction self-sustaining. Within the growing pile, they would add a circular array of uranium oxide in long tubes. In the center of this they would drop the neutron source that should trigger the whole reaction.

Von Weizsacker climbed out of the pit, saw Esau standing there and walked over to him. “I now recall the papers I discussed with you earlier, Professor Esau, the last open reports about the American nuclear research.” He wiped his blackened hands on his blackened coveralls.

“They were published in Physical Review, in English. I remember reading them on the underground railway in Berlin. I believe I received a few suspicious glances when people saw me poring over an American periodical. This was in June 1940, I believe. Some scientists had reported using Lawrence’s cyclotron at Berkeley to create element 93 by bombarding uranium. But element 93 is unstable and undergoes beta decay, turning into element 94. That is the one we want. Element 94 is fissionable, and stable, and chemically different from uranium. We can make your weapon. If we can get this pile working.”

Esau could sense von Weizsacker dancing around the real issue. He felt impatient. By focusing on the optimistic good news, von Weizsacker implied that he also had something bad to say. “I know all that. So what is the problem?”

“Well, it will be very difficult for us to make sense out of our measurements from this pile we are building,” he said with no other preamble. Specks of graphite blackened von Weizsacker’s teeth, but the smudges could not disguise his boyish features, his statue-perfect Aryan appearance.

“We are mixing the sizes of the uranium cubes, adding the uranium oxide to the metal, changing the spacing. Too many variables in everything. Normally, we would build successive piles, each one simple and straightforward, with conditions we could understand and attempt to predict. With successive attempts we can add new twists and see how that affects the readings. We will never be able to understand this reaction. It is too complicated.”

Esau met the younger man’s eyes. He sensed that von Weizsacker had been chosen as a delegate from the other scientists. He noticed that the work had stopped. He kept his voice firm.

“I am not interested in understanding it at this moment. I am interested in demonstrating that it will work! Nuclear physics fascinates me as well, but have you not been listening to the radio broadcasts? The constant bombing of Frankfurt. The American General Eisenhower announcing the unconditional surrender of Italians, and then Italy declaring war on Germany!

“I must deal with the Reichminister of Armaments, who in turn must deal with the Führer. Everyone wants a useful weapon now. Understanding can come later.” Esau turned to go back to his office, but stopped. “When will the pile be ready?”

Von Weizsacker shrugged. “They are still hooking up the counters, and we will need to take measurements at successive stages of the assembly to see how far we must go to achieve criticality.”

Esau kept staring at him, waiting for an answer.

The younger man stopped, thought a minute, then nodded. “Late this evening, I would guess.”

“Good. I will be in my office.”

The man who had discovered nuclear fission, Dr. Otto Hahn, had been chosen the de facto leader of the Kaiser-Wilhelm group. Esau fostered this impression, since he respected Hahn. And Hahn seemed more interested in his physics than in using his authority, which was fine with Esau.

The great physicist, though, treated Abraham Esau like a schoolboy to be lectured. Esau’s own grasp of nuclear physics, though considerable, did not compare with the researchers working under him. He forced himself not to act too impatient when Hahn began to teach him about the pile being constructed in the bunker. Hahn ignored the fact that Esau himself had passed along the key bit of information about graphite.

Otto Hahn himself insisted on “clarifying” it to Esau, making sure that the Plenipotentiary understood the enormity of the event about to take place. Hahn stood in Heisenberg’s old office as Esau dutifully watched the great man pace. Hahn began to talk in his quiet voice.

“We know nothing about what the Americans have done, but we can conjecture how to repeat their experiment. In principle at least.” Esau noticed the stubble on Harm’s cheeks. His moustache stood out, and his eyes looked big and sad, bloodshot from too little sleep. “This goes far beyond the tiny laboratory exercises that I did with Herr Strassman and Dr. Lise Meitner—”

“You need not credit a Jew for your discovery, Dr. Hahn,” Esau interrupted, straightening in his seat.

Hahn halted his pacing, raised his bushy eyebrows and turned to Esau. “Lise did much of the work. She had the idea first. She understood long before I did—” He stopped himself, but Esau already knew what Hahn thought. Rumors even said that he had helped Lise Meitner escape to Sweden, but Hahn had never said this aloud.

Esau didn’t want to push him. He needed Hahn’s mind, his ideas, to make a self-sustaining chain reaction. “No matter. We are worried about physical principles now, not political ones.”

Hahn nodded curtly. “So we are. We know that the uranium nucleus can fission, and that it is the scarce 235 isotope that fissions due to slow neutrons. Niels Bohr pointed that out.”

Esau let his eyes fall closed for just a moment. Bohr, the half-Jew. It seemed they permeated nuclear physics.

“But now we cannot be satisfied with causing merely a fission or two just to prove that it can be done. We must make one fission cause another, and another, and another, so that the reaction continues of its own. Then perhaps it can be useful, such as making a uranium burner to produce power. That was one of Heisenberg’s ideas.”

“We wish to make a weapon, Dr. Hahn. Not a furnace.”

“Both work on the same principle. Listen.” He held up one finger, a thick finger, with blackened pores and nails from handling the carbon blocks. It would take weeks to wash everything off. Even after a thorough shower, the pores of the skin exuded graphite dust within another hour.

“In your mind, Herr Esau, picture a mousetrap with a marble balanced just above the spring.” He stepped back and gestured to the empty floor. “Now picture this floor covered with such mousetraps, each one loaded with a marble, each one ready to snap the instant an appropriate signal is received.”

Involuntarily, Esau leaned over and looked at the bare wooden planks of the floor. Hahn glanced around as if suddenly remembering where he was, then he lowered his eyes and fixed his face into a scowl. “Professor Heisenberg was very good at these thought experiments too.”

Esau said nothing. He tapped his fingertips together and waited for Hahn to continue.

“Now, I will stand outside this room full of mousetraps…” Hahn stepped back, holding one hand up and keeping a gap between his fingers as if holding something. “I have a marble in my grasp. I toss it into the room.” He mimed the gesture.

“The marble in my hand is like a neutron that I send into our reactor. Each of our mousetraps, cocked and holding their marbles, is like a uranium nucleus waiting to fission.

“My marble strikes a mousetrap, setting it off. The spring snaps up, sending my initial marble and its own marble flying into the air. Each of those two marbles strikes another mousetrap, sending two new marbles into the air, plus the same two all over again. Now we have four marbles launched in different directions, heading to different targets. And it repeats again, and again, all in a few seconds! It is like a firestorm, yes? Suddenly the air is filled with flying marbles. The sounds of clacking and springing and snapping!

“This intense reaction will continue for only a moment until all the mousetraps have sprung. All the marbles fall to the floor. Do you see how much energy I have released by simply tossing one particle?” He snapped his black-stained fingers. “That is how your bomb will work, all in an instant.”

Hahn stepped back into the office. “But that is not how our first chain reaction must work. We cannot have everything used up in an instant. We need the reaction to continue in a much slower, controlled manner, because we are using the excess flying marbles to build our new element 94. How do we do this? How can we control such an inferno?

“Imagine perhaps the room filled with cocked mousetraps again, but most of them are not loaded with marbles. Only a few of them. The rest are bare. We must get the right amount of mousetraps loaded—the right amount of uranium-235 in the mixture—and we must also space the mousetraps at the appropriate distances from each other so our result is that on average each marble that strikes a mousetrap causes exactly one more marble to fly in the air. In this way the reaction will continue at a controllable rate for as long as we require it.”

Esau smiled. “Most elegant.”

“The universe is elegant,” Hahn answered, “but secretive. It is up to us to unravel these secrets. In times of war we must unravel them faster than we might like.”

“That is the right attitude, Dr. Hahn.” Esau smiled in a way that might have been considered patronizing.

Hahn stiffened. “Professor Esau, I have already invented one terrible weapon in my life. During the Great War, Fritz Haber and I were the first to consider using poison gas against the enemy. Phosgene, chlorine gas, mustard gas. We were the first. It was our idea. Fritz Haber’s wife was a chemist herself, the first woman ever to receive a degree from Breslau University. She despised her husband’s work. She called it an abomination of science.”

Hahn lowered his eyes, letting them sink deeper behind his bushy eyebrows. “Dr. Clara Haber committed suicide when her husband refused to stop his work on our ‘super weapon.’ “

Esau decided to show compassion in his voice. “I am sorry to hear that.”

“Fritz Haber told me that a scientist belongs to the world in times of peace, but to his country in times of war. So now it is a time of war, and once again I must turn my work to the benefit of Germany. No matter what it does to the rest of the world.”

He stared at his fingers. “I like to consider myself a gentle man, but if you count all the victims of poison gas in the Great War, I already have the blood of over a million people on my hands.” He raised his eyes. “Please don’t treat me as if I am not aware of what we are doing here.”

He glared at Esau once, then left the office.

“It will go critical in the next few layers, Professor Esau.” Esau blinked, startled. He had fallen asleep with elbows sprawled on the wooden desktop. He glanced at von Weizsacker waiting by the door, then he looked at the clock. It was just past two in the morning. “I will be there shortly.” He blinked sleep away from his eyes.

A few moments later he ran along the gravel path to the bunker. Inside, naked bulbs flooded the pale walls and graphite-dusted floor, making it look like a bad black-and-white photograph. Two men continued to assemble the pile; the rest stood waiting behind the cinder-block observation wall that would shield them from stray radiation.

The pile had filled the deep pit. Graphite bricks and chunks of uranium stood in a blocky, somewhat spherical configuration. Neutron counters placed at various locations clicked from the presence of stray particles by the natural uranium decay. Otto Hahn and Paul Harteck stood beside opposite detectors, recording neutron counts as each layer was added to the pile.

Diebner climbed down from the pile. “That is the last layer, according to our calculations.” He kept his voice neutral. “If it doesn’t work now, we must begin again from scratch.”

Suspended above the pile from a chain on the ceiling, six tubes of uranium oxide hung partially inserted within the mound of black bricks. They would be the last pieces to enter the reacting pile. Von Weizsacker stood by a lever that would release a massive counterweight in case of an emergency; the weight would fall and yank out the uranium oxide rods, bringing the pile back to a subcritical state. As an added safety measure, Diebner and Harteck had mounted a drum filled with boric acid solution over the pile; in an extreme situation they could dump the solution into the pile, where the boron would swallow up all the free neutrons and smother the chain reaction. Esau winced at the drum’s precarious position. An accident could spill the boric acid into the graphite bricks, ruining the ultra-pure carbon that had been so difficult to obtain.

“Are we ready to begin?” he asked.

The others looked to Hahn, who handed his notebook to someone else. “Yes. First we must add our neutron source. Spontaneous neutrons should be sufficient, but this will make sure the reaction commences.” He raised an eyebrow. “We are tossing our first marble into the room, Professor Esau.”

Esau nodded.

“Then we will drop the remaining uranium oxide rods into the pile. This should bring us to criticality. The reaction will be self-sustaining.”

Esau folded his arms across his chest. “You may proceed.” But Hahn had already gone to the equipment piled along the walls, opening a small wooden case lined inside with lead foil. He withdrew a thin glass cylinder.

“This neutron source contains radon gas and beryllium powder. You may find it ironic that the Nazis confiscated it from the laboratories of Frederic and Irene Joliot-Curie in Paris.”

Diebner laughed. He had taken many of the Joliot-Curie notes from their laboratories, claiming the discoveries as his own. No one else said anything.

Hahn climbed the ladder to the top half of the graphite pile rising from the pit in the floor. Suspending the glass tube from a thin chain, he dangled it and let the neutron source slide down into the central hole. The clicking of the counters increased. Hahn looked over his shoulder at them. “That is as we expected. Everything is now in place.”

Esau felt nervousness chewing inside of him. “Fine. We are already behind the Americans. No use wasting time. Let’s see if the reactor works.” He listened to the counters rattling and thought of Hahn’s mousetraps.

Paul Harteck spoke up. “Would everyone please step behind the shielding wall? The leaded glass observation windows should protect you.” No one needed to be reminded twice.

“Perhaps we should proceed an inch at a time,” Hahn said, coming around behind the wall. “We will gain more information that way.”

Esau crowded up so he could see through the narrow window. “We can repeat the experiment later if you require such niceties. For now, we must see if all of us have a future here! If we do not show success with this, certain people will be very upset.” He turned to von Weizsacker. “Lower the uranium oxide.”

Von Weizsacker looked to Hahn, then Diebner, as if searching for someone to counteract Esau’s orders, but no one would speak out loud. Some of the assistants edged toward the door. Von Weizsacker released the catch on the chain, letting the six rods of uranium oxide fall into place inside the pile, bringing the pile beyond its critical limit.

The neutron counters went wild, rattling and roaring. Any attempt to keep track of individual counts failed in an instant. Esau could see no apparent difference from watching the pile.

“The reaction is self-sustaining!” Hahn cried.

Paul Harteck stood on the opposite side of the room behind another barricade, staring down at his counter. He had to shout over the noise of the cheering and the neutron counters. “It is still climbing.”

The pile looked unchanged, but the neutron counters insisted that something wondrous kept happening at the core. They had succeeded! With only minimal information, they had reproduced the triumph of Enrico Fermi a few months earlier. Perhaps the German program would not remain so far behind at all. He couldn’t wait to send a telegram to Reichminister Speer.

The counters continued to buzz with their bombardment of flying neutrons. The air itself felt hot to Esau.

“It is still climbing!” Harteck repeated. This time his voice held a greater urgency.

Hahn did not seem alarmed. He gestured to von Weizsacker and raised his voice. “Remove the rods. We now know it will work.”

Von Weizsacker released his emergency lever and the counterweight fell a few inches. The chain grew taut with a metallic ringing, but the six uranium oxide rods remained in place within the pile.

Everyone instantly fell silent. Von Weizsacker yanked on the chain, adding his strength to the counterweight. “Thermal effects!” he said. “The rods have expanded with the heat. They’re snug inside the holes and we can’t get them out. Stupid!”

“Pull!” Esau shouted. He kept remembering Hahn’s mousetraps and the marbles flying through the air, all released at once.

“It would be good to stop this now,” Hahn said with a ragged edge to his voice.

“If the reaction continues, it will melt the rods, maybe even the uranium metal. It could start the graphite on fire,” von Weizsacker said.

“All the readings are completely off scale,” Harteck shouted across the room. “We never thought it would be like this.”

“Dump the barrel!” Diebner shouted. “Use the boric acid!” He ran to the release cord himself.

“No!” Esau clapped his hands. “That will ruin everything!”

Esau added his own weight to von Weizsacker’s, pulling to draw the uranium oxide rods upward. Hahn also helped. Together they strained, and the top layer of graphite bricks buckled, shifted apart, and finally the uranium oxide rods jerked upward, glowing a dull red. Black bricks of graphite slid from the top of the pile, knocking others out of place.

The neutron counters slowed from a sound like crackling fire to a random patter of clicks. Paul Harteck slumped to the floor behind his small barricade and sat down without heed to the graphite dust on the boards.

“Well that was interesting,” Hahn said.

“It was just a start,” Esau said, raising his voice so they could hear him. He slapped one fist against the palm of his hand. “But now we are on our way.”

10 Los Alamos December 1943

Autumn colors had turned the cottonwoods and alders around Los Alamos a brilliant yellow, but the pinon, ponderosa pine, and mesquite remained dark green. The rocks were tan, streaked with blood-colored stains.

Elizabeth sat with Fox on a pile of boulders under a broad cottonwood, eating a lunch she had packed for the two of them. It made her feel annoyingly domestic to do so. The wind made a loud whisper through the trees, but the rest of the world lay in heavy silence around them.

“Nobody tells me anything,” Elizabeth said after a long lull in their conversation. “They treat me like a stupid clerk, when I know as much about what they’re doing as anyone else.” She pulled out the green ribbon Mrs. Canapelli had insisted she wear in her hair, letting the long reddish strands fall loose and free. “I try to talk about the war with some of the other women, and they couldn’t care less! Roosevelt, Churchill, and Stalin just met in Teheran—the women I work with didn’t even know where Teheran was!”

Fox glanced sidelong at her. He had always refrained from asking questions of her, though he must know something was amiss with her. He said, “You are quite unusual, Elizabeth. You do have a more intuitive grasp of physics than half the people here, and you don’t just let the men do all the talking about politics. Maybe you’d best watch yourself. You’ll begin to stand out, and you don’t want that.”

“What?” Elizabeth raised her eyebrows, wondering what he was thinking. Terror spun through her, but he couldn’t possibly know who she was.

“I said intuitive grasp. Not women’s intuition—that’s altogether different. You catch on to an idea and extrapolate conclusions better than most of the physicists I know.”

“Thanks.” She leaned back on an elbow, still uneasy. “So why the compliments? And why now?”

Fox smiled thinly. “Maybe it is the season. A girl is like Nature, showing a side of herself that changes in time. Who would have thought these aspens would turn a brilliant yellow—or that a pretty girl like you could be so complex, so deep.”

Elizabeth cringed at being called a girl. But Graham Fox, with his suave British accent, was no lounge lizard on the make. He was… sincere. This placed Fox in an entirely new light for her. She decided to change the subject to something just as dangerous, but in a different way.

“Um, so, has the project slowed down at all with the death of Teller?” Elizabeth tried to keep her voice conversational to cover how eager she was to find out what she herself had changed.

Fox looked across the canyon, toward the finger of the mesa known as Bathtub Row, where the most important scientists occupied small homes originally built for the boys’ school, each equipped with its own bathtub and plumbing.

“No,” he said, then shook his head. Fox sounded downcast, which surprised her. She had shaken him out of his romantic thoughts. “Teller was merely a theoretician, and Oppie allowed him to work alone on a fusion bomb idea. I doubt that that’s practical for at least another decade.

“Work on the actual Gadget is going as it should. We’re just waiting for plutonium from the Hanford, Washington, plants and enriched uranium from Oak Ridge, Tennessee.” He sighed. “Teller may have been brilliant indeed, but at this point we can recover from losing him.”

Fox bit his lip. “Now Oppenheimer—he is the fulcrum on which everything pivots. Oppie knows all the scientists, he is familiar with what they’re working on. He understands the problems. He knows how difficult the calculations are. He keeps his office door open, and anyone can talk to him. He listens.

“But he’s also got the ear of General Groves, who’s pushed everyone to the edge, demanding results. The scientists wouldn’t be able to tolerate Groves for a single day. Oppie’s the perfect bridge between the government and the scientists. Without him, the Project would fall flat on its face.”

Fox paused, refusing to look at her as he spoke. “Sometimes, I ponder what might have happened if he had been standing behind the projectile test instead of Teller.” Fox stared down at his half-eaten sandwich.

Elizabeth gazed off into the bright delineated canyon. She heard a few birds, and the wind rustling through the trees. Far off, the sounds of Los Alamos seemed distant and irrelevant.

During the winter’s first snowfall, gray clouds made the afternoon dreary and claustrophobic. Elizabeth stood wearing a borrowed pink sweater on the dormitory porch. The frantic pace of the Project grated like fingernails on a chalkboard, and she knew she had to get away, if only for a while.

The Los Alamos stables were on the other end of town, but Elizabeth didn’t mind walking there. She had put on the worn pair of jeans she had kept packed since the night she arrived here in 1943. It didn’t matter that the other women wore long skirts—she was not going to ride a horse in a dress.

The walls of the stable had been covered with scrap wood and pieces of corrugated sheet metal left over from the Quonset hut barracks. A few trees stood on either side of the building, but they hung still. No breeze caused the settling snowflakes to swirl in the air.

Elizabeth slipped through the half-open main doors and smelled horses, hay, and manure. Splashes of light spilled through the four-paned windows and the chinks in the walls. Dust motes trickled through the light.

“Can I help you, ma’am?”

She turned to see a gray-haired, dark-skinned Indian beside one of the horses. He stared at her with a perplexed but uninterested gaze. She had heard of Roger—who apparently had no last name—the Indian taking care of the dozen or so horses maintained for the people on the Project. Roger had worked on a dude ranch near Espanola and impressed Oppenheimer during one of his boyhood trips here; Oppie had pulled strings to get him transferred to Los Alamos.

“Yes, I need a horse saddled up,” Elizabeth answered. “I want to take a ride for the afternoon.”

Roger squinted as if he couldn’t believe his eyes. “Do you need an escort, ma’am? I’m sure we could find one of the guys who’d be willing to—”

“No! Thank you, but I’m perfectly capable of handling a horse myself.” She recited her cover story. “I come from Montana—you have to take a horse if you want to get anywhere.” In truth, she had done quite a lot of riding around the New Mexico mountains. If Jeff had known how to ride, they would not have needed to backpack all the way around to destroy the MCG site… so long ago.

“One of the Project scientists, uh, Dick Feynman, told me I was working too hard,” she continued. “Said I should take a few hours off, go for a horseback ride. It’ll feel good to be on a horse again.” Elizabeth didn’t know if Feynman’s name would carry any weight with Roger, but it couldn’t hurt. She didn’t want people to suspect that she might be thinking for herself—that didn’t seem to be expected of the women around Los Alamos.

Roger shrugged and put his callused hands on his hips, studying the horses in the stable. Elizabeth let her eyes adjust to the dimness. She wondered which one was Oppenheimer’s horse; she had not been able to see clearly in the dawn light when he had passed by and waved, months before.

“Let’s see,” Roger said to himself, “you don’t want to take Crisis, that’s George Kistiakowski’s. You probably couldn’t handle him. Oppie might take his own horse out… no, that’s tomorrow. He usually goes riding down into Bandelier. You could go there if you like. It’s designated a National Monument, but restricted to Project folks these days. It’s almost always empty, especially now that it’s getting cold.”

Roger hefted a saddle lying in the corner and staggered over to three horses that stood munching on a pile of hay in front of them. “Proton, Neutron, and Electron—these are sort of community horses. You’re welcome to take one of them.”

He set the saddle down beside a palomino that gleamed as if it had just been groomed, then picked up a red-and-white-checkered pad and straightened it on the palomino’s back.

“This one’s Proton. He’s probably your best bet.”

Roger hummed low in his throat as he draped the saddle over the pad. Elizabeth watched him, saying nothing, as he tightened the cinch strap, tugged on the stirrups, then mounted the headstall over Proton’s ears. Giving the palomino the bit, Roger handed the reins to Elizabeth.

“All yours, ma’am. Don’t ride him too hard.”

Elizabeth went to Proton, let him sniff her hands, and ran her palm over the pale patch of his nose. She stood on the left side, grabbed the reins and the palomino’s blond mane, then stepped into the stirrup. She swung over the horse’s back, adjusted her sweater, and squeezed Proton’s ribs with her thighs.

“Ah, yes,” she whispered to herself. “This’ll be fun.”

“Remind you of Montana?” Roger said, patting Proton on the flank to get him moving.

Elizabeth cantered the horse out of the stable doors and turned him around, feeling his strength under her, as if she were finally in control again.

The sky overhead still looked gray, and snow continued to fall, but it seemed a gentle snow, not a storm to be feared. Roger looked up at the clouds and nodded, but then turned to her. “You be back by dark. Make sure now, and be careful.”

Elizabeth crouched over the horse, putting her face beside its pale mane and its ears. Smiling, she urged the horse into a gallop away from the stables. Roger waved to her, but she was too engrossed in the ride to acknowledge him.

Proton seemed excited as he moved down the trail. Elizabeth felt the wind whipping her hair with cold gusts of impending winter. She shivered in her pink sweater, but it felt good.

She wanted to ride and keep moving, just to get away from the Project, but she had nowhere to run. She could never go back to her life before—she had not the slightest idea how that might be accomplished. She was stuck here in the past, but it didn’t matter so much anymore, not after six months. Her life had changed before, and she had adapted. She could change herself… and if that proved too difficult, she would just have to change her surroundings instead.

She left the clustered temporary buildings of Los Alamos behind and galloped along the trail. Without the dusty streets and soldiers and barbed-wire fences, the wind brushed against her skin, and she inhaled deeply. The mountains were clean and filled with the hint of ozone. All seemed silent and pristine.

The paths had been used by the old Los Alamos boys’ school and some of the dude ranches; rangers from the Santa Fe National Forest patrolled them occasionally. Now, men taking a break from the Project rode around the mountains carrying rifles to shoot jackrabbits. Oppenheimer himself had spent much time in these mountains.

Elizabeth headed southeast toward where the town of White Rock would eventually be built. She thought of the sprawling Los Alamos National Laboratory that would creep out to here. Many of these areas had been restricted to her before.

Proton galloped along the trail. Snow fell and began to stick to the ground, whitewashing the landscape with a soft covering. As an hour went by, Elizabeth suddenly realized where her subconscious had led her.

She used the reins to tie Proton to a low mesquite bush. The wind had picked up, but the snow slackened off.

The sky looked a darker gray, and she had no doubt that it would keep snowing throughout the night.

She wondered what would happen if a real blizzard hit the fledgling town. In Elizabeth’s former life, the snow plows would be gearing up to clear the mountain roads, schools might close. If the routes got too bad, the scientists who lived in White Rock might have difficulty driving the ten miles up the Hill to Los Alamos. But now everything was deserted.

The walls of Pajarito Canyon towered high and steep, prehistoric in their total absence of any human marking. The Anasazi Indians had been here centuries before. In the main canyon of Bandelier National Monument, Frijoles Canyon, they had grown their beans and chills, raised their sheep. The Anasazi had left abandoned cliff dwellings, much like those at Mesa Verde in Colorado. The Anasazi had disappeared, though—vanished, just like all the equipment from the MCG test she and Jeff Maple had sabotaged in this very canyon.

She hadn’t been back to Jeff’s grave in nearly half a year.

Proton snorted and pulled back, dissatisfied and looking for something to do. The reins held, and he tilted his head up to eye Elizabeth.

She stared down the length of the canyon. There, she could see the rough path she and Jeff had used to descend to the canyon floor, coming in behind the fences and waiting for the Los Alamos security men to depart, waiting for the time when they could destroy the equipment.

Elizabeth hated everything that had made their actions necessary.

She saw the mound of rocks she had piled over Jeff’s body. No one would ever come to take him away. Some of the rocks had been disturbed, possibly by coyotes or birds, but the grave seemed to be intact. A drifting of snow clung to it now; the storm would cover his burial place like a shroud.

Elizabeth didn’t want to go closer. She hated to be afraid to come near Jeff, but she didn’t want to see what was left of his body. She wanted to remember him sleeping beside her, making love to her in anxious desperation on the night before the Livermore demonstration. She wanted to remember kissing him, brushing tongues on the canyon rim as they planned their descent and sabotage. She wanted to remember him holding the sledgehammer high like… Conan the Peace Activist.

Elizabeth squeezed her eyes shut. She didn’t like to think of hauling him to his grave, his eyes closed and burned from within, his skin melted from being caught on the edge of the explosion that had hurled her half a century back in time. She didn’t want to think of Jeff dead because of her, because of fighting the juggernaut of weapons research. All of it had started here, and now, in Los Alamos during World War II.

She hunkered down on the cold ground and picked up a handful of loose stones. As if trying to wake Jeff, she tossed them toward the indentation in the cliff wall, scattering the pebbles on his cairn. His sacrifice had not made much difference.

She remembered the Livermore protest. It hadn’t made any difference either.

She had tried more and more desperate acts. Here in 1943, in the heart of the Manhattan Project, she had done even more. Her miscalculations had led to the death of Edward Teller. But the Project still moved along. The war still went on, unchanged as far as she could tell. Berlin was being bombed, endless fighting was going on in the Pacific, Russia was surging back and recovering terrain lost to the Nazis. All of that would be insignificant once the atomic bomb came onto the scene.

How much more would it take?

“You have to think of your future,” Jeff had told her when she first considered volunteering to be arrested. “Your actions have consequences, Elizabeth. Think about what you’re doing.”

She didn’t know what to think anymore.

Graham Fox, who reminded her of Jeff in many ways, had said,’ ‘Oppenheimer is the fulcrum on which everything pivots. Without him, this Project would fall flat on its face.”

As the snow picked up once more, Elizabeth recalled the documentary clip she had seen, the grainy black-and-white picture of Oppenheimer grinning after the Trinity test, reciting, “I am become death, the shatterer of worlds….”

Oppenheimer had known what he was unleashing! He recognized the consequences, the destruction of his creation. And still he went ahead! If that wasn’t evil, she didn’t know what was.

Elizabeth squeezed her eyes shut. Everything felt silent, as if the world were holding its breath, waiting for her decision.

She had asked Ted Walblaken for advice once—she couldn’t even remember now what the problem had been, but it was before he had known about the cancer, back when he would have punched out any “smelly longhair” who spoke a bad word about United Atomics or the defense industry. But Elizabeth remembered the answer Ted gave her, hearing the words in his own voice as if he could stand there right now and talk in her ear.

“You gotta do what you gotta do,” Ted had said, “and damn the consequences.”

She tossed more stones at Jeff’s grave. Melting snow-flakes made tracks along her cheeks, like tears. But Jeff said nothing, gave her no suggestions from his silent grave.

How much more would it take? The answer, difficult as it seemed, stared her in the face. As she turned to go, Elizabeth realized she had to do what she had to do. It wouldn’t be hard to steal one of the hunting rifles back at the Project. She made plans to return the next day.

Dawn came late in Frijoles Canyon. The sun shed light onto the canyon floor a full hour before the clear rays poured over the sheer walls, illuminating the sparkling new snow.

Elizabeth stirred in the abandoned cliff dwelling where she had spent the night, shivered, and sat up. She blinked, then rubbed a hand under her eyes. The cold snapped her awake and she shook her head.

Taking the stolen hunting rifle in hand, she leaned forward to the adobe window opening. She had to be ready at any time. She didn’t know when Oppenheimer would come riding through.

It had snowed all night, making her solitary vigil hushed and cold. She had slept in one of the crumbling Anasazi ruins in Bandelier, curled in the corner and trying to stay warm. She didn’t dare light a fire; she wanted to leave as little evidence as possible. Elizabeth had thought that far ahead at least.

In her time, all the cliff ruins of the Long House had been restored and reinforced to withstand the depredations of tourists. The Park Service had rebuilt joints with concrete instead of crumbling adobe; steps and trail markers had been cut into the path; safety guardrails lined all the dangerous ledges.

Not now, though—she lay awake in the ruins; rodents sought shelter in corners, and snow piled in ledges on the rocks. It felt like spending a night in a haunted house. Somehow, that seemed appropriate.

Late the previous afternoon, she had ridden back to the stable, returned Proton to Roger and thanked him. She went to the women’s dorm, telling Mrs. Canapelli she might be working odd hours for the next day or two, then had gone to bed early.

After midnight she crept out again, stole a different horse from the stables—Roger might suspect it was her if she took Proton again—and snatched one of the hunting rifles.

She would be hunting something far more important than a rabbit.

Everything seemed so easy, which she found to be a bizarre contradiction of the insipid propaganda posters warning of spies. The Project workers seemed so comfortable in their trappings of security, they couldn’t believe anyone would try the smallest action against them.

Oppenheimer would learn otherwise.

The canyon floor remained deserted early in the morning. Up near the mouth of the canyon a curl of smoke rose from the ranger’s station. Frijoles Canyon Lodge sat on the other side of the creek, a place for the Project scientists to stay when they needed to escape for an evening. It had been run by a civilian family before the war, but the Army had appropriated it when they took over the mountain site.

Morning birds began to sing in the trees, fluttering in the pines and cottonwoods below. From her vantage partway up the slope, she could see the only entrance to the canyon. Some of the adobe structures had been partly excavated a few decades before, when the National Forest Service had run the park. She could see wall lines and piled bricks from the ancient, rounded plaza of the Tyuonyi ruin, highlighted by the snow.

Scrub juniper, pinon pines, and mesquite poked up on the floor and the canyon walls. Above her the beige tuff wall rose straight and unmarred, unscalable over the line of cliff dwellings, but she had toiled down a different trail that reached the ruins. She had left her horse tethered for the night near some scrub grass on the rim. She realized she might need to escape quickly.

Elizabeth looked up and down the canyon, tense already. She tossed aside the horse blanket she had used to keep herself warm, smacked her lips, and thought of how much she wanted a thermos of hot coffee. She didn’t know whether thermos bottles had been invented yet. It frightened her to think of the possibility of people inventing an atomic bomb if they couldn’t even manage a thermos….

She felt her stomach tighten with fear. She had rationalized everything so nicely the day before. Jeff would have been proud of her reasoning. It had made sense then. She tried to drive away her doubts.

This time, at least, she did have a chance to make a real change. Perhaps it would be enough, in a different timeline, to bring Jeff back, to make his death unnecessary. She didn’t know how he would have decided the question himself.

Waiting.

Roger had said Oppenheimer would ride down to Bandelier this morning. But what if he had gone the other direction from the visitor’s center? Perhaps he went down to the Rio Grande instead, only a mile or so downhill from the canyon floor, to look at the waterfalls.

Then she would just have to try again a different day.

Ted Walblaken had waited as the cancer permeated every part of his body. He had waited to die, waited for United Atomics to admit their error, to make changes so nobody else would suffer the same way. He had died waiting for that to happen.

Elizabeth stood up, leaning the rifle beside her. Her hands melted a spot on the snow piled along the rounded sill of the window opening. An abandoned bird’s nest was tucked in the logs supporting part of the ceiling. She watched her breath steam in the chilly air.

Hoof beats. The snow muffled all sounds, but the absence of other noises amplified the clopping and jingling. Many of the birds in the ponderosa pines stopped their morning songs.

Elizabeth leaned back into the shadows of the cliff dwelling. She could bide her time. Oppenheimer had to come this way. The narrow canyon floor would lead him right in front of her.

The sun creeping over the canyon rim made the shadows stark and the colors garish. The bright snow hurt her eyes. Jagged clumps of lava tuff looked like nightmarish sculptures; they blocked the view of the trailhead.

She swallowed. Her throat tightened.

By her one action, she was about to save uncounted lives, and it would cost only one. Didn’t that make sense?

Oppenheimer rode into view, straight and aloof on a sleek brown Appaloosa, the one Roger had indicated in the stables the day before. Oppie wore gloves and a red flannel shirt. His floppy brown hat covered his eyes.

She watched the gangly way he moved, sucking on a cigarette, then tossing it into the snow. He cocked his head up, squinting to the top of the canyon wall. She could see his protruding Adam’s apple. He glanced toward the cliff houses, then away.

He rode alone. She looked for other riders, escorts or rangers to watch the all-important director of the Manhattan Project. But no, they suspected nothing. In such isolation in the New Mexico mountains, what did they have to worry about?

Elizabeth slid the rifle out of the window opening. Crumbling adobe pattered to the snow outside the wall. She looked down, then squinted at Oppie. He pulled up his horse, as if to present a better target for her.

This would change everything.

She thought of a poster she had helped assemble for the Livermore Challenge Group, showing hideously burned corpses from Hiroshima, silhouettes of human beings reduced to blast shadows against a wall in Nagasaki. A hundred thousand dead from the first blast, another fifty thousand from the second.

What about the fear inspired for decades with the Cold War, the production of bigger and better bombs? The children brought up—as she had been—in mortal fear of the air raid sirens, the civil defense training films showing how to “duck and cover.” What about the people, like Jeff, who had given their lives to resist the spread of nuclear weapons?

Jeff lay dead, in an unmarked grave, thrown back in time to twenty years before he was supposed to be born, as a consequence of the ball J. Robert Oppenheimer had started rolling.

/ am become death, the shatterer of worlds.

Elizabeth had a chance to wipe the chalkboard clean, start over with a new and better equation.

She squinted along the rifle barrel. She steadied it with her left hand and rested the stock against her shoulder. She felt her hands shaking. She would have only two shots.

She centered Oppenheimer’s head in the sight. Below, he waited for her, unsuspecting, enjoying the morning.

Oppenheimer was the fulcrum, Fox had said. His actions, his brilliance made the Manhattan Project work. He had known what he was doing as visions of nuclear fire danced in his head. Perhaps it was a game to him, an interesting physics question to see how much destruction one man could cause. She couldn’t think of him as a worthy human being. Right now, Oppenheimer was a target, a domino she was going to tip in the opposite direction, away from the chain of events she knew would happen if she didn’t act.

Mrs. Canapelli had chatted about being friends with Oppie and his wife Kitty back in Berkeley, how he had gotten her the job to chaperone the women’s dormitory after her husband had died. Mrs. Canapelli had spoken of him with fondness. Elizabeth found it difficult to imagine him as the same man, this madman.

Oppenheimer turned to look back toward the cliff dwellings. The hat cast his face in shadow, but she could see part of a smile.

Elizabeth tightened her finger on the trigger. It would be just like pushing The Button, the big red button that would launch the world into a nuclear holocaust.

Oppenheimer sneezed, startling her.

With a flinch, she recentered his head along the gun sight.

Oppie hesitated, looked around as if to make sure no one was watching, then wiped his nose on the sleeve of his red flannel shirt.

Elizabeth froze, paralyzed by the simple, human gesture. Oppenheimer blinked as if he were a little boy who had gotten away with bad manners, and then rode on.

Elizabeth couldn’t fire.

Her finger slid away from the trigger and she rested the rifle barrel on the sloping window opening. Her bones turned to rubber and she felt faint. Black spots danced in front of her eyes.

She had wanted to kill a man! The trigger had been a hair’s breadth away from sending a bullet through Oppenheimer’s head. Elizabeth began to shiver.

The rifle dropped out of her hand, slid along the adobe wall of the ruined dwelling and struck the rocks below.

The gun discharged, sending a sharp thunderclap through the narrow canyon.

Oppenheimer jerked up on his horse. He gawked around, frozen like a jackrabbit for an instant of terror, then wheeled his Appaloosa and rode off back toward the ranger station at full gallop. His hat flew off behind him as the horse kicked up snow.

Cursing herself, Elizabeth stood up, grabbed her blanket, and scrambled out the broken back wall of the An-asazi dwelling. She didn’t know how close the rangers would be. Stupid! Oppenheimer would send an entire hunting party after her. She had to hurry up the steep path along the canyon wall to reach the top, mount her horse and flee back to Los Alamos.

She didn’t know what she had done. Stupid!

She couldn’t take it back now. She had failed.

As she scrambled up the path, she kept shuddering, feeling her crisis, her indecision. “I’m sorry, Jeff,” she whispered, then hurried before she could hear the sound of approaching guards.