The child's smile returned. It lowered the muzzle of its gun towards Floyd, its fingers coiled around the grip like pale eels.

There was another high-pitched volley of bullets.

The child shook like a doll, suspended in the air as rounds tore through it. Auger kept firing, squeezing

the trigger until the gun fell silent, its muzzle aglow. The remains of the child, shredded clothes and lacerated flesh melded into an inseparable ma.s.s, flopped to the tunnel floor like a butcher's offcut.

Floyd stumbled to his feet and followed Auger through the gap in the wall.

"Floyd, you can't come any further."

"You think I want to take my chances out there? They'll a.s.sume I was the one shooting at them."

"Trust me: you're still better off trying to reason with them."

"They'll shoot first," Floyd said.

She growled in frustration. "You follow me, you're getting into very deep water."

"I'll take that chance."

"Then close the door, before those men get here."

He did as he was told. "You think they saw us come in here?"

"I don't know," she replied, her voice still weak and her breathing ragged and irregular. "But they'll want to know what happened to us. They'll comb every inch of the tunnel now. They're sure to find that door."

"I hope you have another way out of here, in that case."

"So do I."

They were in a much narrower tunnel, with no rails on the floor. No train could have fitted inside it. It was too low for Floyd to stand up in, and even though he ducked, he kept barking the top of his head against the rough-hewn ceiling. Auger led him onward, pausing now and then to gather her strength. "We were lucky," she said. "The children don't see very well in the dark now. As they get older, their vision deteriorates."

"How old are they?"

"They've been here for at least twenty-three years, maybe more, getting more decrepit every day."

"Something tells me you're ready to talk now."

"In a moment, Floyd, you're going to have all the answers I always said you didn't want."

TWENTY-SIX.

Floyd made out a softening of the darkness ahead, like the first suggestion of day in the final hour before dawn. The voices of the search party did not sound far away, as if they were close to the other side of the door. Auger was right: it wouldn't take them long to find their way through, especially if they thought they were going after killers.

"So who sent these children? Who are they working for?"

"I don't know for sure. I wasn't briefed on that part. My people sent me here to do a simple job, which was to recover Susan White's box of papers. They didn't tell me there'd be complications."

"But they knew there would be?"

"My bosses? Yeah. I'd say there's a pretty good chance they knew more than they told me."

"Sounds as if you were sold down the river, Auger."

"That's more or less my conclusion."

"You ready to tell me who you are yet, and who your bosses are? They weren't straight with you, after

all, so you don't owe them anything."

"If they'd been straight with me, I'd never have come here."

They reached the source of the light. There was a heavy door set into one wall of the shaft, huge and

thick and circular, like the door to a safe or one of the armoured hatches on a tank. The pale light spilled through the crack where the door had not been fully closed. It had a wavering quality, like reflections from a swimming pool.

"This isn't good," Auger said. "That door should be closed by now."

"What's happened to those friends of yours?"

"I was expecting them to be here by now-a few reinforcements, at the very least. Until last Friday we

had a whole team here."

"What happened on Friday?"

"The children penetrated the shaft, broke in via a tunnel of their own. Killed Barton and Aveling, two of

my colleagues. Skellsgard took a hit, but she was all right. I got her out of here, told her to send help back for me. I had to leave the door open when I left since there was no one left on the other side to lock it."

"When were you expecting this help to arrive?"

"It should have taken sixty hours, minimum. The earliest the cavalry could have arrived was sometime

around midnight last night, but there may have been a delay at the other end before anyone could set out on the return journey. They would have arrived on the other side of that door, able to shut it properly."

"Maybe if we go through that door, we'll have a better idea of what's happened."

"You're not going to like what's through that door," Auger warned.

"I'm in for the rest of the game. Let's do it."

They nudged the door open wide enough to squeeze through. Floyd helped Auger up on to the metal lip,

into the raised area beyond. He followed her, squinting against the strange, shifting light that filled the chamber.

"Now help me close the door," she said.

They worked the door into its seal, then Floyd turned the hefty wheel that locked it from the inside.

"That'll keep them out for a good few hours," Auger said. "They'll need to bring cutting gear down into the tunnel, and there's no telling how long it will take them to break through even when it arrives."

"But they'll get through eventually."

"Yes, but you only have to hold out down here for three days or so. By that time, we'll have sent people through to help you get back to safety. You'll find provisions and water in the next room."

"What next room?"

The chamber they were in was the size of a one-car garage, its walls gouged from dark, glistening rock. The floor was scratched metal. Several cabinets and work benches were arranged around the perimeter, set with what Floyd recognised as wireless transmitting equipment. There was a lot of it, and it was wired together in surprising ways, but there was nothing that looked like super-secret spy gear of the kind he had expected. The only odd thing in the room-and it was, admittedly, more than a little odd- was the peculiar plaque or mirror hanging against-or rather set into-the rear wall. It was the source of the light: a perfectly blank, flat surface as tall as a man that none the less conveyed a subtle, queasy sense of depth and shifting perspective. The surface was framed by a heavy construction that merged seamlessly into the walls of the cave. The frame was moulded from a translucent material like dark honey, twinkling with a suggestion of shimmering machinery buried deep within it.

It looked like nothing he had ever seen in his life.

"This is the censor chamber," Auger said, peeling away the sticky wad of Floyd's jacket that was serving as a bandage, rearranging the fabric and then pressing it hard against her wound. "There's first-aid gear here, but we'll have more to choose from on the other side of the censor."

"The what?"

"That thing," she said, pointing to the source of the wavering light. "We call it the censor. It's like a checkpoint. It lets certain things through, and stops other things. I think we'll both be safer on the other side of it."

"Keep talking," he said, transfixed by the shifting, resonating surface.

"We don't know exactly what rules it applies," Auger said, a remark that did nothing to rea.s.sure him. "It's pretty strict about what it lets into Paris. But it doesn't seem to be so picky about the things it allows through the other way."

"You're talking as if you don't even know how that thing works."

"We don't," she said simply. "We don't even know who made it, or how long ago."

"This is getting way too strange for me," Floyd said.

"Then turn back and face those men." Auger nodded at the censor. "I'm not even sure it will let you through anyway."

"Will it let you through?"

"Yes," she said. "I've been through it three times already, no harm done. But we're not the same. What applies to me won't necessarily apply to you."

"How different can we be?"

"More than you know. But there's only way to find out. I'll go through first and wait for you on the other side. If you haven't come through after a minute or two, I'll..." But Auger could not finish whatever it was she meant to say.

"What is it?" Floyd asked.

"It isn't that easy. We've never seen the censor refuse a living thing. I don't know what it will do if it decides not to let you through." Auger swallowed. "It might not be pretty. When we tried to bring machines through from the other side-weapons, communications gear, that kind of thing-it usually didn't allow it. That's why we call it the censor."

Floyd began to feel as if he had walked into a parlour game with only a vague idea of the rules. "It blocked them somehow?"

"Destroyed them," Auger said. "Turned them into useless lumps of metal slag. Randomised them on the atomic level, erasing even any microscopic structures. Nothing worked any more. The only things it let us bring through were simple tools. Digging equipment. Knives. Clothes. Paper money. That's why there's nothing fancy in this room. Everything you see had to be found in Paris, smuggled in here and then cobbled together to serve our needs."

Floyd stared at the flickering surface, hypnotised by it. He had been pushing Auger for answers since he had met her, always with a certain preconception in his mind, and now that he was getting the truth-in measured, drip-fed doses, admittedly-it was nothing like what he had imagined. It was the kind of truth that made him want to shrivel up and hide under a stone. The worst part was that there was a weary conviction in her voice that told him that none of this was a hoax. She was being straight with him now, or at least as straight as she dared.

There was something under Paris that had no right to exist, and Auger wanted him to step through it.

"Will I like what's on the other side of that thing, if it allows me through?"

"No," she said. "You won't. I'm pretty d.a.m.n sure of that. But you'll be safer there than here. Even if those men make it into this room, they'll need some persuading to step through the censor. I think you can hold out until I return with help."

"Then let's get it over with. You go first. I'll see you on the other side."

"You're ready for this?"

"As ready as I'll ever be."

"I've got to go, Floyd. I hope you make it through."

"I'll be fine," he said. "Now off you go."

She pushed herself through the censor, awkwardly swinging by her good arm from a rail positioned above it to give her momentum. The glowing membrane stretched at first like a sheet of rubber, resisting her progress. Then it snapped around her until she appeared embedded in it, only the back of her head and one elbow and heel showing. Bruiselike ripples surrounded her form. Then she was gone completely, the membrane flexing and rebounding like a trampoline, and Floyd was alone.

He pushed a finger experimentally against the drumlike surface and felt the faintest electrical tingling. He pushed harder. The tingling intensified. He stopped, removed his finger and pulled a toothpick from his pocket. Holding the toothpick by one end, he pushed the other tip into the surface until he felt that tingling again. He pulled out the toothpick and held it up for inspection. It appeared unharmed in any way, and when he slipped it into his mouth it tasted like all the others he'd ever chewed. Something still made him throw it away.

He pushed his finger in again, up to the quick at the base of his fingernail, and ignored the tingling as it sank into the surface as if into wet clay. The layer flexed back, until he had pushed a depression into it as deep as his forearm. Suddenly fearful, he released the pressure before the membrane could snap around him.

"Just do it," he said, and threw himself at the surface.

Floyd came through. He fell in a crashing sprawl on the other side, smashing his bandaged head against cold metal flooring. All he could do, for at least a minute, was lie perfectly still as multiple pain signals. .h.i.t his brain, where they were filed into pigeonholes, like letters in a sorting office. There was pain from his head, where he had hit the floor. His mouth hurt like h.e.l.l-he must have bitten his tongue or the inside of his cheek, or something. There was pain from his knees and one elbow, and from the bruises on his back where he had fallen against the rails. His arm hurt where the child had pressed its shoe, holding him to the ground. But there was no shrill agony of amputation. He might have lost a finger or two, perhaps: he could believe that. But when he flexed his hands, even his fingers seemed to be more or less intact. Bruised and raw, certainly, but he could still play something, even if it had to be the maracas from now on.