When the snake robot had patched her up, it carried Auger into the passenger compartment of the battered ship. Floyd was already inside, strapped into the rightmost of the three chairs, carrying on his conversation with Skellsgard. Inside, the ship did at least look new, despite its external appearance. The seats were heavy affairs of padded black material, with enormous cross-webbed buckles and head restraints. In front of each seat, folded aside until the occupant was in place, was a complicated arrangement of controls and screens, markedly more bulky and robust than anything Floyd had seen so far. There were very small windows surrounded by yet more banks of controls, lights and screens. Behind the padded seats was a very narrow companionway leading—as far as Floyd could tell—to a set of storage lockers adjacent to a washroom about the size of a small kennel, with an even smaller kitchen/medical cubicle next to it. He knew it was a medical cubicle because of the Red Cross symbol on one of the white equipment boxes bolted to the wall. The rest of the ship was not accessible from the passenger compartment, and must have been taken up with machinery and fuel, or whatever else it needed to function. Pumps and generators chugged and hummed, and occasionally there was a thump or whine from some hidden mechanism.
“How much has Auger told you?” Skellsgard said.
“Damn little.”
“Where did she tell you this ship was going to take her?”
“She didn’t,” Floyd said.
“Huh.” This seemed to amuse the other woman no end. “So what’s your best guess?”
“My best guess is that we’re going to take a trip down some kind of underground tunnel. Maybe we’ll come out in the Atlantic and make the rest of the trip by submarine. Or maybe we’ll be met by a squadron of flying pigs.”
“Something tells me you have doubts.”
“Call me a stickler for detail,” Floyd said, “but I couldn’t help noticing you mention something about Earth and Mars back there.”
“Those were codewords, you silly boy.”
“They’d have to be,” Floyd said.
“All right. Listen up, and listen good. This is what you absolutely need to know, if Auger can’t make herself useful. You’re going to be in this thing for thirty hours, give or take. It’s going to be rough. How rough will depend on luck and the robot getting you off to a good start. But if I were you, I wouldn’t take too many trips to the head.”
“I have a weak bladder.”
“Tell Floyd about the manual controls,” Auger said as the robot eased her into the left-hand couch, contorting its body to reach inside the ship.
“Floyd,” Skellsgard said, “I want you to fold down the console panel in front of your seat, so that it’s across your lap. Then latch it in place.”
“Done,” Floyd said.
“Get your hand around the joystick. Squeeze it. The display to your right should show a green-on-red stress-energy grid. Got that?”
Floyd did as he was told. “I’m seeing a grid,” he said. “I’m also seeing a lot more than that.”
“That’s fine. Now, do you see the blue diamond-shaped marker, between the two yellow brackets?”
“I’m seeing several diamonds.”
“Move the joystick laterally. The icon that moves is the one you need to worry about. Ignore the fixed markers for now, and don’t worry about all them teeny little numbers.”
“The grid is changing. It’s like it’s drawn on hot toffee, and I’m dragging a spoon through it.”
“That’s the idea. Now flip up the red cover on the back of the joystick and get your thumb on the right pressure pad. The right, not the left. Squeeze it gently and tell me what happens to the grid.”
“The grid’s moving. Everything’s moving, drifting to the left.”
“That’s expected. What you’re seeing is a visual representation of the tunnel geometry ahead of the ship, approximately a light-microsecond downstream from the throat. The system is showing you a prediction of your drift based on that geometry.” Floyd opened his mouth to speak, but Skellsgard was ahead of him. “Don’t worry your pretty little head about the details. The key thing is that the geometry isn’t stable, and if we let the ship fly itself, it’ll keep nosing to one side of the tunnel or the other. You don’t want that to happen, since the tidal stresses become exponentially stronger the closer to the sides you get. Now, the ship’s guidance spines can absorb glancing impacts with the tunnel walls, but the telemetry I’m seeing at this end tells me that those spines took quite a pounding on the way over. Hull armour looks pretty crumpled as well.”
“The telemetry’s right,” Auger said. “I’m not sure the ship will hold together, even without additional stresses.”
“We’ll have our fingers crossed at this end. In fact, we’ll have everything crossed.” Resigned to the inevitable, perhaps, Skellsgard’s voice suddenly became hushed and businesslike. “The important thing is that the uploaded software patches should do a pretty good job even with the changing geometry, so you won’t have to fly the ship all the way home.”
“That sounds good,” Floyd said. “I don’t think I could manage to do it for thirty hours straight.”
“But you’ll still have to override the autopilot now and then. The simulations we’ve run at this end show that the guidance system doesn’t cope well with abrupt changes in tunnel geometry, especially when the shear angles exceed seven hundred and twenty degrees.”
“Doesn’t cope well?” Floyd asked.
“It crashes.”
“The ship crashes?”
“The software.”
“The what ware?”
Auger interrupted. “She means the guidance system will stop working without any warning.”
“Can I start it again?”
“Yes,” Skellsgard said. “You’ll need to implement an immediate reboot. That’s the easy bit—Auger can show you how to do that. The difficult bit is that you’ll need to get the ship back on course before you scrape the sides of the tunnel.”
“Scraping sounds painful. And what kind of angle exceeds seven hundred and twenty degrees, anyway?”
“The kind you’ll get a headache thinking about, so don’t.”
Floyd moved the joystick again, getting the feel of it. “How long will I have to get us back on track before we scrape?”
“Depends. Ten, maybe fifteen seconds. That should be enough time for you to override and correct your trajectory. There’ll be an audible alarm when the guidance system crashes, telling you you’re about to become an interesting smear on the inside of the tunnel.”
“Anything else I need to know?”
“Only about a lifetime’s worth, but that’s the way it is. Just keep an eye on the grid and try to anticipate the drift gradients before they sneak up on you. You should see bunching of the grid lines. The ship’s response time is slow, so make sure you keep your control inputs small and discrete, giving the ship time to answer the helm before you make another correction.”
“Now you’re talking a language I almost understand.”
“Have you ever flown transatmospherics?”
“I don’t think so,” Floyd said.
“He used to be a trawlerman,” Auger said. “Before that I think he drove barges of some kind. They’re a kind of boat,” she added.
“Did those barges turn on a dime?” Skellsgard said.
“No,” Floyd said. “Matter of fact, they took about a nautical mile to slow down. And you had to anticipate every bend in the river long before you saw it.”
“Or else you’d scrape the banks,” Skellsgard said, nodding approvingly. “Well, all you need to do is think of this ship as a big old barge with some unusual characteristics, and the tunnel walls as banks you really, really don’t want to scrape. Can you get your head around that?”
“I can try,” Floyd said.
“Then maybe you can bring this baby home in one piece after all.”
Floyd shrugged, letting the joystick return to its central position. Skellsgard was making a big effort to sound optimistic, but her cheerfulness was paper-thin. “Say,” he began, “if you’re talking to us now, why can’t you talk us all the way home? You know, the way the guys in the tower talk down planes in the movies when the pilot’s had a heart attack and some poor Joe is at the controls?”
“We lose this link as soon as we shoot a ship into the tunnel,” Auger said. “She’ll be off-air until we arrive at the other end.”
“But I’ll be waiting for you,” Skellsgard said. “I can still monitor the condition of the link, even if I can’t talk to you. I don’t think any of us is going to get much sleep in the next thirty hours.”
“Don’t worry about us,” Auger said. “We’ll get home safe and dry. Just make sure you’re bright-eyed when we pop out the other end. I’ll need another ship prepped and ready to make an immediate return trip, and a robot ready to fly it.”
“I thought you said you needed medical attention.”
“I’m not talking about myself. Floyd can’t stay with us on the other side. We still have to get him back into Paris.”
Skellsgard nodded. “Yeah, let’s try to contain the damage, shall we?”
“I’m all for damage containment,” Auger agreed.
“Me, too,” Floyd said. “But why do I feel as if I’m the damage?”
“Skellsgard,” Auger said. “Listen to me. I think I know why Susan had to die. The stuff they were building in Germany? I think they were parts for a resonant gravity-wave antenna.”
“Mmm,” she said, frowning. “Tell me more.”
“Three spheres dotted around Europe, cooled down close to absolute zero and rigged to vibrate if gravity waves pass through them.”
“You say there are three of these things?”
“One in Berlin, one in Milan, one in Paris. I think they’re using three as a means of screening out background noise: any signal registered by all three of them must be significant.”
“Three would also give you a handle on direction, if you had accurate enough clocks at all three sites.”
“Maybe they have that, too.”
“It’s still tricky, Auger. You’d need to hang these things in vacuum and hook up some pretty sensitive acoustic amplifiers before you had a hope in hell of getting anything useful out of them.”
“But it’s all at least feasible using E2 technology, with a few refinements. A lot easier than building something like a laser interferometer or an orbital test mass, when no one’s invented the laser or the artificial satellite yet.”
“You have a point there. You know about Weber? Guy from around the same time period as E2. He built a room-temperature bar detector using a chunk of solid aluminium. Same basic principle.”
“Did it work?”
“Not really. It wasn’t sensitive enough. But the principle was sound, and it paved the way for the cooled-down resonant detectors that did work, about fifty years later.”
“Someone’s jumped the gun here,” Auger said. “They’ve built one, maybe even operated it.”
“Who do you think is behind it?”
“Slashers. The same ones who must have come through during the Phobos occupation. At the very least, they’re a part of it.”
“Why, though? What’s the point? We can do all the gravity astronomy we need from the vicinity of the real Earth.”
“It isn’t about astronomy,” Auger said. “I think it’s about triangulation.”
“You’re losing me, Auger.”
“Think about it. No kind of electromagnetic radiation can get through the shell of the ALS, which means that there’s no way of determining the real location of E2 in the galaxy. But gravity’s different. It seeps through. Now, so do neutrinos, but building a directional neutrino detector is at least as difficult as building a directional gravity-wave antenna, and a lot trickier to keep out of the public eye.”
“But why… oh, wait. Now I see. You rig up this thing and start looking for known gravity-wave sources. Bright high-period derivative binaries: double degenerates on the death spiral, that kind of thing.”
“Yes,” Auger said. “You pick up their resonant frequencies—which are as unique as fingerprints. You measure how strong they are and with three spheres you can calculate which direction they’re coming from. You put the pieces together, crunch some data, and you have—”
“The physical co-ordinates of the ALS,” breathed Skellsgard.
“They may already have them by now,” Auger said.
“But why? Why would anyone go to all that trouble?”
“Because they want to find it very badly,” Auger said. “From the outside.”
“Jesus,” Skellsgard said. “What are they actually thinking of doing with that information?”
“That’s the bit that worries me. Look, maybe it’s nothing, but for some reason Susan wrote ‘Silver Rain’ in one of the letters she intended to send to Caliskan.”
Skellsgard said nothing for several seconds. “Jesus squared. Are you sure?”
“I think they might be trying to inject it into the ALS. It’s a nano-weapon, so it can’t come through the censor. That only leaves them one option: find the ALS and drill a hole in it.”
Skellsgard blew air out through pursed lips. She had no more expletives, no more profanities. “Who do you want me to tell? You reckoned Susan had some doubts about who she could trust.”
“I think she was right to. I’m taking a risk even talking to you, of course. Now I’m going to take another risk and suggest you get this information to Caliskan as soon as possible.”
“I’ll do what I can. Like I said, it’s not exactly business as usual at this end of the pipe.”
“I hear you—just do your best. In the meantime, see if you can check the feasibility of my little theory. Maybe there’s a snag; maybe it can’t be a gravity-wave antenna at all.”
“I’m on the case,” Skellsgard said. “Gives me something to take my mind off the bad news, at least.”
“Glad to be of service.”
“You take care of yourself, Auger. I still owe you one.”
Thirty minutes later, they had the ship prepped—as Auger put it—and ready for departure. The cradle had rotated the entire craft through 180 degrees, so that the view through the forward-looking cabin windows showed the glassy shaft that ran from the main bubble into the wall of the chamber. Beyond the shaft, the walls became mirrored, converging not to infinity but to a kind of iris. The robot had disembarked, slinking away with maggotlike undulations of its pearl-necklace body. Floyd could not see it at all now, but Auger assured him that it would be attending to the details of their departure, managing several desks at once.
“Skellsgard?” Auger said, from her chair on the left side of the cabin. “You still on the line?”
“Still here…” Momentarily, her voice broke up into staccato shards, as if they were hearing pieces of her message out of sequence. “…but you might want to cast off sooner rather than later. Conditions are getting seriously sub-optimal.”
“Shouldn’t we wait things out?” Auger asked.
“You’ll be relatively safe once you clear the throat.”
“Why does she not fill me with confidence?” Floyd asked.
“Never mind,” Auger said. “Robot: you got that injection sequence ready?”
The piping voice of the machine assured her that all was ready. “Throat stability is locally optimal,” it said, whatever that meant.
“You buckled in, Floyd?”
“I’m ready.”
“There’ll be quite a kick. Be prepared.” Then she raised her voice. “OK, robot, inject us whenever you want.”
“Injection in five seconds,” the machine said.
Ahead, the iris cranked open. Floyd narrowed his eyes against the intense, roiling glare that spilled between the opening blades. The light flowed in strange, sicklelike patterns down the mirrored shaft. From somewhere behind the ship, the mechanical sounds intensified, and he heard a sequence of thuds and clunks like some enormous clock gearing itself up to chime.
“Three seconds,” the robot said. “Two. One. Injecting.”
Floyd’s bruised spine yelled a protestation into his brain. He felt as if a family of gorillas was practising xylophone exercises on his vertebrae. He started to say something, some useless moan of animal discomfort, and then found that he did not have the strength to speak; even his lungs felt as if they were being squeezed like bellows. His head and neck mashed back into the seat restraints and he felt a mouthful of drool spill down his chin. His vision darkened around a central core of brightness.
They were moving.
They were moving so quickly that they were not even in the chamber any more. They had already traversed the glass shaft and the mirror-lined part of the tunnel and were speeding through the heart of the opening iris, into the unimaginable fury of the light beyond.
That was when it got really bumpy.
The pressure forcing him into the back of the seat had abated and in its place was a dreamy lightness-of-stomach feeling, as if they were falling, but the ship was now lurching from side to side, each violent movement accompanied by a tooth-grinding rattle of ravaged metal. This, Floyd thought, was how it felt to grind past an iceberg in an ocean liner. He imagined scabs of the ship’s hull breaking off into the bright inferno of whatever it was they were flying through.
He didn’t think it very likely that it was a tunnel under Paris any more. Or even a tunnel under the Atlantic Ocean.
“I’m closing the shields now,” Auger said. “The view doesn’t help much. Especially not after ten hours of it.”
She touched a control above her head, using her good arm, and iron eyelids snicked down over the windows. Interior lights came on, bathing everything in a low-key glow. Floyd watched the grid pattern, his hand ready to close around the joystick.
“I’ll look after it for now,” Auger said, taking hold of a similar control on her side of the cabin. “You can watch and learn.”
“There are a couple of questions I really need to ask,” Floyd said.
“OK,” Auger said. “I guess you’ve earned them.”
“Where is this tunnel taking us?”
“It’s taking us to Mars,” Auger said. “Specifically to Phobos, one of Mars’s two natural moons.”
“So it wasn’t a codeword after all.”
“No,” she said.
“I figured that part out, for what it’s worth. I also decided that I don’t think you’re a Martian.”
“No, I’m not.”
“But you’re not from Dakota, either.”
“No, Dakota was a lie. But I am from the United States.” She offered him a nervous smile. “Just not the one you were thinking of, although I suppose you could call them distant political relatives.”
“And your name?”
“That bit was true. My name’s Verity Auger, and I am a citizen of the United States of Near Earth. I’m a researcher for the Antiquities Board. I was born in the orbital community of Tanglewood in the year twenty-two thirty-one. I’m thirty-five and divorced, with two kids I don’t see as often as I should.”
“The odd thing is,” Floyd said, “I don’t doubt you for a moment. I mean, what other explanation could there be?”
“You seem very relaxed about it,” she said.
“Given all that I’ve seen, the only possible explanation is that you’re a time traveller.”
“Ah,” Auger said. “That’s the problem, you see. I mean, time travel is definitely involved here, but not in quite the way you’re thinking.”
“It isn’t?”
“No. But you’re half-right. You see, one of the two people in this ship is a time traveller. And it isn’t me. Do you want me to carry on?”
“I thought I had you figured out for a moment,” Floyd said.
“One step at a time,” Auger told him. Then there was a shriek from some part of the instrument panel and a dozen red lights started flashing in synchronisation. Auger bit her lip and pushed her joystick to one side. Floyd felt the ship veer: a sickening feeling like a car hitting ice.
“Was that a… what did she call it? Smash?”
“That was a software crash, yes,” Auger said. She flipped a bank of switches, then threw back a glass cover to press a large red button. “And this is the reboot sequence, so pay attention.”
“We’ve only just left.”
“I know,” she said. “We’ve got thirty more hours of this to get through. I think the ride home is going to be a lot more interesting than I was hoping.”