She managed to say, “I need to puke.”

“You need to listen to what I’m going to tell you.”

His voice sounded different now. Colder, flatter. Of course it did. He had dropped his mask. Or exchanged it for a different one. “I NEED TO PUKE!”

“Puke, then. Puke on the floor between your legs. Do it now, because if you keep making useless noise I’ll tape your mouth.”

She puked on the floor, not because he said so but because she couldn’t help it. It had been a long time since her last meal. All that came up was a sour brown dribble.

But it helped clear her thoughts. She felt as if she had floated a little way above her aching body.

“You know what I am,” the Leo-thing said. “You expect I’ll lie to you. But I’m not trying to convince you of anything. At this point it doesn’t matter what I want.”

Leo had been the hypercolony’s eyes and ears inside the Correspondence Society, privy even to Werner Beck’s secrets. He could have killed any of them or all of them, any time. Cassie wondered why he hadn’t.

“This van is packed with industrial explosives. Dynamite, the kind they use for blasting in mines. My father’s invention—”

“He’s not your father. You never had a father.”

“My father’s invention is a useless fantasy, but the dynamite is real. You need to know how to use it. Listen to me. I’m going to tell you what a blasting cap looks like, how to attach it to a stick of dynamite and how to fuse it. I don’t have time to tell you twice, so pay attention. You have to remember this.”

“You must be insane,” Cassie said.

But the creature went on talking.

Cassie was aware of the knife. It kept drawing her eye. It was a big knife, maybe ten inches long, in a leather sheath. The Leo-thing kept it wedged between his left leg and the driver’s seat, where she would have a hard time reaching it even if her hands were free.

The Leo-thing talked about how to crimp a blasting cap and how to ignite a fuse. She wondered what the point of all this could possibly be.

“But it’s not enough,” he said, “to ignite some explosives. To do real damage you have to know where to plant them. You have to think about other incendiary material in the environment, the fire that will follow and how it will burn.”

Did these assertions count as lies? Because the simulacra were liars: she had learned that from the Society; it had been implied on every page of her uncle’s book. But no, not liars exactly; they were simply indifferent to truth, had no conception of truth. She said, “What do you expect me to blow up?”

“If you weren’t smart you wouldn’t be here. I could have taken Beth. But you’re smarter and braver than Beth. Where do you think we’re going?”

Her hatred flared up fresh and hot. “Into the fucking desert!”

“Where exactly?”

“How should I know?”

“We’re going to the breeding facility.”

The place Eugene Dowd had described. She had not permitted herself that thought. It was too terrifying. She strained against the seat belt, tried to swing her bound and cramping hands toward the door latch.

“Stop. Calm down. Cassie, think. You know what your aunt said about there being two kinds of sims, two entities competing to control the hypercolony?”

Deep breaths. She closed her eyes. No point wasting her strength. What was left of it. She nodded.

“I want to destroy the facility. It doesn’t matter why. But I can’t do it alone. In fact I can’t do it at all. All I can do is give you a chance.”

She waited for him to go on. Lies, but maybe in his lies she could discover something she could use, some means of leveraging an escape.

“You know what I am,” the Leo-thing said. “I’m not just this body. I’m something larger. I’m older than you can imagine, Cassie. I’m weaker than I was, and I’m being eaten from the inside out. It’s past time for me to die. I want to die. I want you to help me die. Don’t you want that too?”

His voice sounded like the road under the wheels or the thin air skimming past the windows. It sounded like the white moon rising and the hollow basins of the salares. It sounded like the stars.

Where the highway met the railhead in a tangle of fenced yards and boxcars, Leo followed a two-lane road that veered away from San Pedro de Atacama and bisected the desert like a surveyor’s line. He had started talking about dynamite and blasting caps again. Cassie’s attention faded in and out. Words and fragments of words echoed in her head like frantic poetry.

She forced her eyes open and discovered that time had passed, though the sky was still dark. This endless night. Her hands were numb and tingling. Her body ached. Had she been having a nightmare? No. This was the nightmare.

She shook her head to clear it. The reek of sim blood had grown so intense that she no longer smelled it so much as felt it, a pressure in the air. The Leo-thing’s leg was dark with moisture.

The paved road gave way to gravel and ahead of them there was a huge moonlit mound, a wall of earth and debris that Cassie recognized with a kind of anesthetized dread as the breeding ground Eugene Dowd had described. Distant figures moved on the rim of it, black silhouettes against the blue-black sky. Some moved on two legs, some on four.

“Only a few minutes now,” the Leo-thing said.

He unsheathed the knife and leaned toward Cassie. She avoided his eyes and focused on the blade. It was bright and smooth and wickedly sharp. It moved in concert with Leo’s arm like the sting in a scorpion’s tail.

With his free hand he clasped her bound wrists. “Do you remember what I told you? Wake up, Cassie, wake up, this is important!”

She shook her head in incomprehension.

“I can’t hurt them,” Leo said. “There’s very little left of me. But I can shut them down. I can put them to sleep. And I’ll sleep too. Every living thing that operates under the protocols of the hypercolony will stop functioning. For a little while. Only a little while! You’ll be alone. So it’s up to you. You know what to do, right? Do it. And do it quickly.”

Was this the same Leo who had stroked her hair in a bed in a room on the long road down the spine of the Americas? The same Leo who had kissed her and told her to sleep well? Sleep well, Cassie.

He put the blade between her legs and sliced the duct tape binding her ankles. She watched the back of his head as he moved, his fine hair matted with sweat and road grime, the vulnerable nape of his neck. She thought about kicking him but couldn’t summon the strength.

On the distant berm, creatures both two-and four-legged began descending toward the motionless van. They moved with grace and deliberation and an eerie speed. When they passed into the moon-shadow of the hill they seemed to disappear altogether.

Leo drew back and looked at her. “I’m going to cut your hands loose. Hold still.”

She held still. He braced her arms with his body and slit the knot of tape in a single motion. Her hands began to burn as blood flowed back into them. She was still strapped into the seat.

Leo glanced down the road, where the sims were running toward the van, closing in on it, advancing into the glare of the headlights as if they were riding a wave of light. The six-limbed ones made her think of huge crabs, scissoring the air with their claws.

Leo turned the knife in his hand and grasped it by the blade. Cassie saw a line of blood well up from the web of skin between his thumb and index finger. He offered her the handle. She stared at it.

“Take it,” he said.

“What?”

“Take it! Take it, Cassie! Take it!”

She grabbed it from him, gripped the hilt with both hands and aimed the blade at him, her heart hammering in her chest.

“Now cut yourself loose from the seat belt.”