"And human nature being what it is..." Floyd said.

"It was late July twenty seventy-seven," Auger said. "For the last couple of years, we'd been busy releasing tiny machines into the environment in an attempt to fix the climate. The planet had been heating up for more than a century, as we spewed c.r.a.p into the atmosphere. The oceans were screwed up. Sea levels were rising, flooding coastal town and cities. There were freak storms. Some places got colder. Some places got hotter. Some places just got...strange. Really strange. And that was when some coalition of d.i.c.kheads had the idea that we ought to try squirting some intelligence into the weather system. 'Smart weather,' they called it."

"Smart weather," Floyd echoed, shaking his head incredulously.

"'Big dumb idea' would have been closer to the truth. It was going to solve all our problems. Weather we could turn on and off, weather we could boss around. We seeded the oceans and the upper atmosphere with tiny floating machines: invisible to the eye, harmless to people. Unthinkable numbers of them, self-replicating, self-redesigning, self-coordinating. They reflected radiation here; absorbed it there. Cooled down this place, warmed up that place. Made clouds bloom and disperse in geometric patterns, like something from a Dali painting. Made deep-ocean currents bend through right angles and flow through each other, like rush-hour traffic. They even made money out of it, painting thousandkilometre-wide corporate logos across the Pacific Ocean in phytoplankton. They could arrange a local enhancement in the colours of the sunset, as viewed from your private island. A little more green tonight, sir? No problem at all. And you know, for a while, it actually worked. The climate stabilised and began to creep back to pre-twenty fifty conditions. The icecaps began to grow again. The deserts began to retreat. The hotspots began to cool down. People began to move back to cities they'd abandoned twenty years earlier."

"Call me a fatalist," Floyd said, "but I sense a 'but' coming along."

"It was never going to work. Late in twenty seventy-six there were rumours-unconfirmed reports-of some weather patterns refusing to follow orders. Ocean circulation events no one could turn off. Clouds that wouldn't disperse, no matter what you did to them. A persistent obscene symbol off the Bay of Biscay that had to be airbrushed out of every satellite image. It was clear-even though no one was admitting it-that some of the machines had evolved a little too far. They were more interested in their own self-preservation than obeying sequenced shutdown-and-disa.s.semble commands. So you know what the coalition of d.i.c.kheads did, for an encore?"

"I'm sure you're about to tell me."

"They came up with some even cleverer, slyer machines and said they'd sort out the first wave. And so they were given authorisation to inject these into the environment as well. Trouble is, they only made things worse. Teething problems, they said. Meanwhile, the out-of-control weather events were getting more freakish by the hour, far worse than anything we'd had to deal with before. Now it was mechanized weather. By mid-twenty seventy-seven, they'd thrown eight layers of technology into the fray, and things hadn't improved. But then there was a hopeful sign: in early July of that year, the obscene symbol dissipated. Everyone got very excited, saying that the tide was turning and the machines had begun to return to human control. They all breathed one vast collective sigh of relief."

"Which, I take it, was premature."

"The phytoplankton bloom making up the obscene symbol had vanished for a reason: the machines had eaten the plankton. They'd started using living organisms to fuel themselves. It was against the most fundamental structures built into their programming-they weren't supposed to harm living things-but still they did it. And it got much worse, really fast. After the plankton, they worked their way up the marine food chain pretty d.a.m.n quickly. By mid-July there wasn't much left alive in the entire Atlantic Ocean, apart from the machines. By the twentieth of that month, the machines had begun to attack land-based organisms. For a few days, the whiz kids still thought they could keep a lid on things. They had some small successes, but not enough to make a difference. On the twenty-seventh, the machines digested humanity. It happened very quickly. So quickly it was almost funny. It was like the Black Death directed by Buster Keaton. By the twenty-eighth, with the exception of a few extremophile organisms buried deep underground, there were no living things left alive on Earth."

"But someone must have survived," Floyd said, "or else you wouldn't be here to tell me any of this."

"Some people made it through," Auger said. "They were the ones who'd already left the surface of the Earth, moving into s.p.a.ce habitats and colonies. Primitive, ramshackle affairs, barely self-sufficient, but enough to keep them alive while they coped with the loss of the Earth, and the numbing psychic trauma of what had happened. It was about then that we split into two political groupings. My people, the Threshers, said that nothing like this could ever be allowed to happen again, which is why we rejected the nanotechnology that had led to the development of the machines-and so much more-in the first place. The Slashers, on the other hand, thought that the damage was done and that there was no point in limiting themselves out of some misguided sense of penitence."

Floyd was silent for a few moments, as he attempted to get his brain around everything Auger had told him. "But you told me you're from twenty-two-whatever-it-was," he said eventually. "If all this happened in the middle of the twenty-first century, there's still quite a lot of history you haven't told me about yet, surely."

"Two hundred years of it," Auger said, "but I'll spare you the details. Really, not much has happened. The same political groupings still exist. We control access to Earth, and the Slashers control access to the rest of the galaxy. Most of the time, it's been reasonably peaceable."

"Most of the time?"

"We had a couple of small...disagreements. The Slashers keep trying to repair the Earth, with or without our consent. So far, they've only made things worse. There's a whole ecology of machines down there now. The last time they tried-twenty-three years ago-we ended up having a small war over access rights. It turned messy-really messy-but we patched things up afterwards. It's just a shame about what happened to Mars."

"Nice to see wars haven't gone out of fashion," Floyd said.

Auger nodded sadly. "But in the last few months, things have turned sour again. That's why I wasn't exactly thrilled to discover a Slasher presence in your Paris. It tells me that they're up to something, and that makes me worried. I can't help but think it has to be bad news."

"Wait," Floyd said. "There's something I need to get straight here. A few hours ago you told me you were not a time-traveller."

"That's right," Auger said, tight-lipped.

"But you keep on telling me you're from the future," he said, "born in the year twenty-two-whatever. You've even given me a history lesson about some of the events that have occurred between my time and yours. Mad weather...mad machines...people living in s.p.a.ce..."

"Yes," Auger said helpfully, raising an eyebrow.

"Then you must have travelled back to the present. Why pretend otherwise? This ship must be your time

machine, or whatever you want to call it. Are you taking me back to the future?"

She looked at him hard. "What year is it, Floyd?"

"It's nineteen fifty-nine," he said.

"No," she said. "It isn't. It's twenty-two sixty-six-more than three hundred years into what you think of

as the future."

"You mean it will be when we come out of the other end of this thing. Or have we somehow already entered the future?" "No," she said, with an infinite and alarming patience. "It isn't nineteen fifty-nine now. It wasn't nineteen fifty-nine yesterday and it wasn't nineteen fifty-nine when we met last week."

"Now you're making even less sense than usual."

"I'm saying that your whole existence is..." She grasped for words that would make sense to him.

"Something other than what you think it is. On one level, it's not even true to say that you are Wendell Floyd."

"Maybe the robot should have put you under after all. You're starting to sound feverish."

"I wish it was a fever. That would make life a lot easier for all concerned."

"Not least for me." Floyd scratched at his bandage, wondering if the delusional one was himself. His arm floated free, light as a balloon. It was as if they were falling, as if in a dream. He was going to wake up back in his room in rue du Dragon and laugh all this off with Custine over bad coffee and burnt toast.

One b.u.mp on the head too many, that was his problem.

But he kept on not waking up.

"So let's start with me," he said. "Start with this poor sap named Wendell Floyd. Explain how it is that I might not even be who I think I am."

"Wendell Floyd is dead," Auger said. "He died hundreds of years ago."

That was when an alarm started buzzing somewhere in the cabin. Floyd's hand reached for the joystick, ready to nudge the ship back on course. But Auger shook her head, holding up three fingers in warning. "This is different," she said. "The guidance system is still on-line."

"Then what's the problem?"

"I'm not sure. They only gave me the idiot's guide to flying this thing." Auger threw banks of switches, making the screens light up with different numbers and diagrams. Nothing she did made the audible alarm turn off.

"Any clues?" Floyd asked.

"I don't think there's anything wrong with the ship," she said. "Everything looks good-or at least acceptable-on all boards. And it doesn't look as though it has anything to do with the tunnel geometry ahead of us."

"What, then?"

She threw more toggles, tapping the nail of an index finger against one of the screens and frowning at the avalanche of tiny digits and letters. "Not good," she said. "Not good at all."

"Just tell me," Floyd said, frustration beginning to well up in his voice.

"Something's coming up behind us. That's what this alarm is telling us. The proximity system is picking up some kind of rearward echo. I can't read the numbers well enough to work out what it is, but it could be another ship."

"How could there be another ship?"

"I don't know," she said. "Believe me, I wish I did. The tunnel is vacuum-sealed at the Paris end. Even if it was somehow possible to get two ships into it at the same time-and I'm not even sure the mathematics allows that-then it still can't have happened. There is no other ship in the E2 recovery bubble. We should be the only rat in this drainpipe."

"Something else then? Another machine, but not necessarily a ship?"

"I don't know. Maybe it's some debris we dropped behind us. It was a b.u.mpy insertion, and some stuff probably got knocked off the ship. It might be following us, sucked along in our wake. If we have a wake."

"But why would we not have seen it until now, in that case?"

"That's a d.a.m.ned good question," she said under her breath, as if he was the last person in the world she wanted to know it.

TWENTY-NINE.

Presently, Auger found a way to turn off the audible alarm. Floyd breathed a sigh of relief when the din ended and they were left with the usual churn of cabin background sounds. There was something soothingly maritime about those noises. They made him think of engine rooms: the distant, rea.s.suring throb of diesel power.

"I wish they'd told me how to interpret this junk," Auger said, lines of concentration furrowing her forehead as she stared at the streaming numbers. "It's almost as if the d.a.m.ned echo is getting closer. But that can't be the case, can it?"

"I'll take your word for it," Floyd said, shrugging helplessly.

"If it was debris, it wouldn't be getting any nearer. We should have lost most of it when we slid through the interchange cavern. And given all the uncontrolled collisions it would be experiencing against the tunnel walls, it should be losing ground on us, not gaining it. There also shouldn't be a lot left of it by now."

"So scratch the debris theory. Maybe you're misreading those numbers," Floyd offered. "Or maybe there's something wrong with the ship, making it imagine there's something behind it when there isn't."

"I'd really like to believe that," she said.

"You might be getting worked up over nothing. Fact is, from the little that you've told me, there isn't a whole lot we can do except sit back and enjoy the ride. That's more or less the case, isn't it?"

"Somehow, that doesn't make it any easier to live with."

"Then I'll try to take your mind off things until you can make some more sense of those numbers. We were talking about me, I think: specifically about how I didn't actually happen to exist."

"Maybe we shouldn't go there, Floyd." Auger could not snap her attention from the puzzling barrage of numbers. She kept staring at them with a poised alertness, like someone expecting a flash of gold in a mountain stream. "It was a mistake to tell you what I did."

"Sorry, kid, but you already opened that particular can of worms. It kind of gives a fellow the creeps to hear someone talking as if he died years ago. Are you going to elaborate, or do I have to turn on the charm?"

"Not the charm, Floyd. I'm not sure I could take it."

"Then tell me about these rumours of my death. When, exactly, did they nail me into a box?"

"I don't know," she said. "And I don't even know for sure that you rated a box. I'm afraid Wendell

Floyd simply didn't make enough of a dent in history for that detail to have survived. Remind me how old you are, Floyd-forty, forty-one?"

"Thirty-nine. You really know how to flatter a guy."

"So you were born-when? Some time around nineteen twenty?"

"Spot on," Floyd said. "Which would have made Floyd eighty by the end of the century. But chances are he didn't get to see the year two thousand. He might well have died during the Second World War, or perhaps he lived a happy and peaceful life into old age and pa.s.sed on surrounded by loving family members. Or maybe he ended his days as some crabby, antisocial b.a.s.t.a.r.d everyone couldn't wait to see the back of."

"I've always had a sneaking regard for crabby, antisocial b.a.s.t.a.r.ds," Floyd said. "Whatever happened," Auger said, "it was a human life. He was born, he lived, he died. He probably made some people happy and other people unhappy. He was probably remembered for a few decades after he died. After that, he'd just have been a face in old photographs-the kind that come out when you spring-clean, and you can't quite remember where they came from or who's who. And that was it.

Wendell Floyd. He lived. He died. It was a life. End of story."

"Why do I have the feeling that someone just walked over my grave?"

"Because someone probably did," Auger said. "Or they would have, if your grave wasn't buried under a

few hundred metres of ice."

"Where did the ice come into it?"

"I told you the Earth got screwed up. But never mind the ice. What matters is that at some point during

the late nineteen thirties, something happened to Wendell Floyd."

"A lot of things happened in the late nineteen thirties," Floyd said.

"But the main event is one that you won't remember at all. No one does. But the funny thing is that it happened to everyone at the same instant, and it was the most important thing that ever happened to them in their whole lives. And yet it went utterly unremarked."

"It happened to everyone?"