She felt a flicker of doubt-she'd never killed a man before-but it was not enough to stop her; in a single motion she stepped behind the guard and drew the blade and shoved it with all her strength into his lower back. She felt a stiffening, the muscles of his frame drawing tight, like a bow; from deep inside his throat came an exhalation of surprise.

She felt him die.

Punching through the din, a voice from high above: Peter's? "Theo, run!"

The pump was a throbbing confusion of levers and knobs. Where were Michael and Caleb when you needed them? Mausami picked the largest one-a wild guess, a lever as long as her forearm-and wrapped it in her fist and pulled.

"Stop her!" someone yelled. "Stop that woman!"

As Mausami felt the shot entering her upper thigh-a strangely trivial pain, like the sting of a bee-she realized she'd done it. The flames were dying, guttering around the ring. The crowd was suddenly backing away from the wires, everyone yelling, chaos erupting. The viral had broken away from the last of the cattle, drawing itself erect-all throbbing light and eyes and claws and teeth, its smooth face and long neck and massive chest bibbed in blood. Its body looked swollen, like a tick's. It stood at least three meters, maybe more. With a flick of its head it found Finn with its eyes, head cocking to the side, body tensing as it took aim, preparing to spring, and then it did; it seemed to cross the air between them at the speed of thought, invisible as a bullet was invisible, arriving all at once where Finn lay helpless. What happened next Mausami did not see clearly and was glad that she did not, it was so fast and terrible, like the cattle but vastly worse, because it was a man. A splash of blood like something bursting, and part of Finn went one way, and part of him another.

Theo, she thought, as the pain in her leg abruptly deepened-a wave of heat and light that bent her double. The leg folded beneath her, sending her pitching forward. Theo, I'm here. I've come to save you. We have a baby, Theo. Our baby is a boy.

As she fell she saw a figure sprinting across the ring. It was Amy. Her hair was pulling a trail of smoke; darting tongues of fire were licking at her clothing. The viral had shifted his attention toward Theo now. Amy charged between them, protecting Theo like a shield. Faced with the creature's immense, bloated form, she seemed tiny, like a child.

And in that instant, which felt suspended-the whole world brought to a halt while the viral regarded the small figure before him-Mausami thought: that girl wants to say something. That girl is going to open her mouth and speak.

Twenty meters overhead, Hollis had dropped through the vent with his rifle, followed by Alicia, holding the RPG. She swung it toward the floor, pointing its barrel at the place where Amy and Babcock stood.

"I don't have a shot!"

Caleb and Sara dropped through behind them. Peter snatched Jude's shotgun from the floor of the catwalk and fired in the direction of the two men racing down the catwalk toward them. One man uttered a strangled cry and fell away, tumbling headfirst to the floor below.

"Shoot the viral!" he called to Alicia.

Hollis fired and the second man dropped, face-down, onto the catwalk.

"She's too close!" Alicia said.

"Amy," Peter yelled, "get out of there!"

The girl stood her ground. How long could she hold him that way? And where was Olson? The last of the fires had gone out; people were streaming down the stairs, an avalanche of orange jumpsuits. Theo, on his hands and knees, was backing away from the viral, but his heart was nowhere in this; he had accepted his fate, he had no strength to resist. Caleb and Sara had made it across the catwalk to the stairs now, descending into the melee on the balconies. Peter heard women screaming, children crying, a voice that sounded like Olson's, rising over the din: "The tunnel! Everyone run to the tunnel!"

Mausami lurched into the ring.

"Over here!" She stumbled, catching herself with her hands as she fell to the floor. Her pants were soaked in blood. On all fours, she tried to rise. She was waving, screaming: "Look over here!"

Maus, Peter thought, keep back.

Too late. The spell was broken.

The viral rocked its face toward the ceiling and drew down into a crouch, its body gathering energy like a coiled spring, and then it was flying, lofting through the air. It rose toward them with a pitiless inevitability, arcing over their heads and seizing one of the ceiling struts, body rotating like child swinging on a tree limb-an oddly exhilarating, even joyful image-and landed on the catwalk with a shuddering clang.

I am Babcock.

We are Babcock.

"Lish-"

Peter felt the RPG sailing past his face, the scald of hot gas on his cheek; he knew what was going to happen before it did.

The grenade exploded. A punch of noise and heat and Peter was shoved backward into Alicia, the two of them tumbling onto the catwalk, but the catwalk wasn't there. The catwalk was falling. Something caught and held and they banged down hard, and for a hopeful moment everything stopped. But then the structure lurched again, and with a pop of rivets and a groan of bending metal the end of the catwalk broke away from the ceiling, tilting toward the floor like the head of a hammer, falling.

Leon in the alley, face-down in the dirt. Goddamn, he thought. Where did that girl go?

Some kind of gag was in his mouth; his wrists were bound behind him. He tried to wriggle his feet, but they were tied, too. It was the big one, Hollis; Leon remembered now. Hollis had risen out of the shadows, swinging something, and the next thing Leon knew he was all alone in the dark and couldn't move.

His nose was thick with snot and blood. Probably the son of a bitch had broken it. That was all he needed, a broken nose. He thought he'd cracked a couple of teeth, too, but with the gag in his mouth, his tongue stuffed behind it, he had no way to check.

It was so goddamn dark out here he couldn't see two feet in front of his face. The reek of garbage was coming from somewhere. People were always putting it in the alleys instead of taking it to the dump. How many times had he heard Jude tell people, Take your f**king garbage to the dump. What are we, pigs? A joke, sort of, since they weren't pigs but what was the difference, really? Jude was always making jokes like that, to watch people squirm. For a while they'd kept pigs-Babcock liked pork almost as much as he liked the cattle-but some kind of sickness had wiped them out one winter. Or maybe they'd just seen what was coming and decided, What the hell, I'd rather just lie down and die in the mud.

No one would be coming to look for Leon, that was for sure; the problem of standing up was his to solve on his own. He could sort of see a way to do it, by drawing his knees to his chest. It made his shoulders hurt something terrible, twisted back like they were, and pushed his face, with its broken nose and teeth, into the dirt; he gave a yelp of pain through the gag, and by the time he was done with it, he was woozy and breathing hard, the sweat popping out all over. He lifted his face-more pain in his shoulders, what the f**k had that guy done, tying his hands so tight-and raised his upper body until he was sitting up, his knees folded under him, and that was when he realized his mistake. He had no way to stand. He'd sort of thought he could push off with his toes, jumping his way into a standing position. But this would just send him pitching forward onto his face again. He should have scooched over to the wall first, used it to shimmy his way up. But now he was stuck, his legs jammed up under him, frozen in place like a big dumbshit.

He tried to cry for help, nothing fancy, just the word "Hey," but it came out as a strangled Aaaaa sound and made him want to cough. Already he could feel the circulation going out of his legs, a prickly numbness crawling up from his toes, like ants.

Something was moving out there.

He was facing the mouth of the alley. Beyond it lay the square, a zone of blackness since the fire barrel had gone out. He peered into the dark. Maybe it was Hap, come to look for him. Well, whoever it was, he couldn't see a goddamn thing. Probably his mind was playing tricks on him. Alone outside on new moon, anybody could get a little jumpy.

No: something was moving. Leon felt it again. The feeling was coming from the ground, through his knees.

A shadow streaked above him. He lifted his head quickly, finding only stars, set in a liquidy blackness. The feeling through his knees was stronger now, a rhythmic shuddering, like the flapping of a thousand wings. What the goddamn-?

A figure darted into the alley. Hap.

Aaaaaaaaa, he said through the gag. Aaaaaaaaa. But Hap seemed not to notice him. He paused at the edge of the alley, panting for breath, and raced away.

Then he saw what Hap was running from.

Leon's bladder released, and then his bowels. But his mind was unable to register these facts as all thought was obliterated by an immense and weightless terror.

The end of the catwalk impacted the floor with a massive jolt. Peter, clutching one of the guardrails, barely managed to hold on. An object tumbled past him, clattering end over end before bounding into space: the empty RPG, spiraling a meteoric wick of smoke from its tube. Then something heavy struck him from above, ripping his hand away-Hollis and Alicia, tangled together-and that was that: the three of them were falling free, sliding down the angled catwalk to the floor below.

They hit the ground in a confusion of arms and legs and bodies and equipment, scattering across the floor like balls tossed from a hand. Peter came to rest on his back, blinking at the distant ceiling, his mind and body roaring with adrenaline.

Where was Babcock?

"Come on!" Alicia had grabbed him by the shirt and was pulling him to his feet. Sara and Caleb were beside her; Hollis was hobbling toward them, somehow still carrying his rifle. "We have to get out of here!"

"Where did it go?"

"I don't know! It jumped away!"

The remains of the cattle were strewn everywhere. The air stank of blood, of meat. Amy was helping Maus to her feet. The girl's clothes were still smoking, though she seemed not to notice. A patch of her hair had been scorched away, revealing a raw pinkness of scalp.

"Help Theo," Mausami said, as Peter crouched before her.

"Maus, you're shot."

Her teeth were clenched with pain. She shoved him away. "Help him."

Peter went to where his brother was kneeling in the dirt. He seemed dazed, his expression disordered. His feet were bare, his clothing was in tatters, his arms were covered with scabs. What had they done to him?

"Theo, look at me," Peter commanded, gripping him by the shoulders. "Are you hurt? Do you think you can walk?"

A small light seemed to go on in his brother's eyes. Not the whole Theo, but at least a glimmer.

"Oh my God," said Caleb, "that's Finn."

The boy was pointing toward a bloody shape on the floor a few meters away. Peter thought at first it was a piece of the cattle, but then the details came into focus and he understood that this lump of meat and bone was half a person, a torso and head and a single arm, which lay twisted at an odd angle over the dead man's forehead. Below the waist there was nothing. The face, just as Caleb had said, was Finn Darrell's.

He tightened his grip on Theo's shoulders. Sara and Alicia were lifting Mausami to her feet. "Theo, I need you to try to walk."

Theo blinked and licked his lips. "Is it really you, brother?"

Peter nodded.

"You ... came for me."

"Caleb," Peter said, "help me."

Peter pulled Theo upright and wrapped an arm around his waist, Caleb taking him from the other side.

Together, they ran.

They exited into the dark tunnel, into the fleeing crowds. People were tearing toward the exit, pushing and shoving. Up ahead, Olson was waving people through the opening, screaming at the top of his voice: "Run to the train!"

They burst from the tunnel into the yard. Everyone was making for the gate, which stood open. In the darkness and confusion a bottleneck had formed, too many people trying to shove their way through the narrow opening at once. Some were attempting to scale the fence, hurling themselves against the wires and clawing their way up. As Peter watched, a man at the top fell backward, screaming, one leg tangled in the barbs.

"Caleb!" Alicia cried. "Take Maus!"

The crowd was surging around them. Peter saw Alicia's head bobbing above the fray, a flash of blond hair he knew to be Sara's. The two of them were moving in the wrong direction, fighting the current of the crowd.

"Lish! Where are you going?" But his voice was overpowered by a blast of sound, a single sustained note that split the air, seeming to come not from one direction but from everywhere at once.

Michael, he thought. Michael was coming.

They were suddenly propelled forward, the energy of the panicked throng lifting them like a wave. Somehow Peter managed to keep hold of his brother. They passed through the gate and into another mob of people compressed into the gap between the two fence lines. Someone banged into him from behind and he heard the man grunt and stumble and fall beneath the feet of the crowd. Peter fought his way through, pushing, shoving, using his body like a battering ram, until, at last, they burst free of the second gate.

The tracks were dead ahead. Theo seemed to be rousing, doing more to carry his own weight as they fought their way forward. In the chaos and darkness Peter couldn't see any of the others. He called their names but heard no answer over the yelling of the figures tearing past him. The road ascended a sandy rise and as they neared the top he saw a glow of light coming from the south. Another blast of the horn and then he saw it.

A huge silver bulk churning toward them, parting the night like a blade. A single beam of light shot from its bow, shining over the masses of figures crowding around the tracks. He saw Caleb and Mausami up ahead, racing toward the front of the train. Still holding Theo, Peter stumbled down the embankment; he heard a squeal of brakes. People were racing alongside the train, trying to grab hold. As the engine drew closer, a hatch opened in the front cab and Michael leaned out.