If he had any advantage it was his intimate knowledge of the farm house, its angles, its shadows, its exposed places and its high ground. He hugged the left-hand wall until he reached the landing of the stairway, then leaned into the emptiness beyond the railing with his pistol sighted toward the front door. Nothing. But there was a rattle that might have come from the kitchen.

Ethan’s respect for his opponent was complete. He thought again of Werner Beck dissecting the captured sims, an act that seemed both cruel and vengeful until you realized it was neither—the sims felt no pain and were indifferent to indignity. They weren’t even individuals, in the human sense. They even were less autonomous than ants or termites, mere extensions of the superorganism that had created them: massive, complex, far-traveled, ancient. Not even remotely human, and above all, not to be underestimated.

Ethan hurried down the stairs, mindful that he was exposed to fire from the sim’s automatic rifle. From the bottom of the stairs he could see most of the farm house’s main room, which was empty. Which left the kitchen. The door to the kitchen was closed. He couldn’t remember if he had closed it himself. He had no choice but to announce his presence by throwing it open, pistol ready, thinking with some fraction of his mind of Nerissa: she was armed but terrified, and if he died here—

But the kitchen too was empty. The back door was askew in its frame, hanging by one hinge where the sim had kicked it in. A trail of muddy boot prints led from the broken door to the entrance to the cellar. Ethan looked at the stairwell with dismay. He could only conclude that the sim was down there with Winston Bayliss.

Move, he told himself. He had no choice but to attempt the cellar stairs.

He was halfway down when he saw the sim at the foot of the stairs with its back to him, looking utterly human with its upturned collar, its sagging blue jeans, the nascent bald spot at the crown of its head. The automatic rifle was raised, but not in Ethan’s direction. The sim began to turn as Ethan’s foot hit a creaking riser. But it was no faster than a mortal man. Ethan had been granted that rare gift, an easy target. He squeezed the trigger of the pistol.

Simultaneously, the sim began firing into the darkness of the cellar. In this enclosed space the sound was deafening. Ethan flinched, but not before his bullet took the simulacrum at the base of its skull. The sim’s automatic rifle sprayed a few more bullets, then fell silent. The sim toppled over, inert.

Ethan stood over the body and put a finishing shot into its head. Green matter gushed out, emitting a rank chemical-fertilizer stink.

Then he looked around the cellar, realizing what it was the sim had done: incredibly, it had shot Winston Bayliss.

The creature that called itself Winston Bayliss was still strapped to the chair where Ethan had left it, held in place by coils of duct tape, but its upper body slumped at a nasty angle: the invading sim’s rifle fire had nearly bisected it at the hip. Bayliss was leaking blood and green liquid at a furious rate.

It raised its head and looked at Ethan steadily. “Please,” it said faintly. “Please, will you bandage the wound? We still need to talk.”

Ethan could only stare.

“As quickly as possible,” Winston Bayliss said. “Please.”

The idea of staying here even an hour longer had become absurd. It was past time to leave, and everything would have to be burned. His notes, his video gear, the attic arsenal—the farm house from its foundation to the peak of its mossy roof. Ethan had been preparing for this contingency since his first days here. He had stored a dozen canisters of kerosene in the main floor closet, and every morning he put a fresh book of matches in his hip pocket.

He came up the stairs to the attic and found Nerissa waiting, her pistol aimed at his chest. She lowered the weapon instantly, to Ethan’s relief. The way her hands were shaking, one awkward twitch might have killed him. “Is it dead?” she asked.

He managed to nod. Though for all he knew there might be more on the way.

She relaxed so suddenly that he thought she might lose her footing. She put a hand on a shelf to steady herself.

All this must have been unimaginably hard on her. Ethan had loved this woman once and maybe still did, though the gap of doubt and blame between them had grown vast and was probably unbridgeable. He couldn’t look at her without seeing the Nerissa he had once known: Nerissa across a table in the faculty cafeteria, quoting writers he hadn’t read and whose names he barely recognized, her long hair threatening to interfere with a plate of French fries—her liveliness and her ready smile, then so available, now so completely erased. She looked unspeakably tired. Night was falling and he wished he had a comfortable bed to offer her, but there was much to be done and no time to hesitate. Miles to go, in the words of one of those poems she had liked to recite. Miles to go before we sleep.

He took the first of his dozen jerricans of kerosene into the cellar, where he poured the contents over the corpse of the dead sim and along the floorboards. Nerissa emptied another canister over the firewood stacked under the single window, which he had boarded over, and as she worked Winston Bayliss began to plead with her. “Bind my wounds,” it said. “Take me with you.”

The sim had bled out massively from its human parts, and now it was leaking its greener contents onto the cellar floor. A reeking mess, Ethan thought. But the fire would cleanse all that.

“He’s practically cut in half,” Nerissa said. “The one who broke in did that?”

“Yes.”

“Why?”

“I don’t know.”

“What this thing said, about there being two kinds of sims, do you think that’s possible?”

“I don’t know. Half of what these things do is theater.”

“I can explain,” Winston Bayliss said. “If you bind my wounds. If you take me with you.”

“Maybe we should,” Nerissa said.

Startled, Ethan looked up from the trail of kerosene he had laid. “Are you serious?”

“I mean if it knows something about Cassie and Thomas.”

“Cut off my legs,” Winston Bayliss said. “They’re useless. Tourniquets above the stumps will keep me alive for a time, if you do it quickly.”

Madness, Ethan thought. But Nerissa turned to him and asked in a voice gone steely and indifferent, a voice he barely recognized, “What about it, Ethan? Do you have an axe down here? A hatchet?”

“Jesus, Ris!”

“Because if we burn it we’ll never know why those others wanted it dead.”

“What exactly are you suggesting? That we hack off its legs and, what, put it in the trunk of the car?”

“Well, it would fit,” she said. “If we did that.”

He hoped it was a macabre joke. Or maybe the kerosene fumes were getting to her. But no. He had always known when she was serious. “Ris… even if what you’re suggesting might be useful, and I’m not admitting such a thing even for a second, we’d be taking a crazy risk. We don’t know for sure what’s looking out through that thing’s eyes, but what ever it is, I don’t want it watching us.”

“That needn’t be a problem,” the sim said.

Ethan and Nerissa looked at it. The wounded sim had worked its right hand loose from its bonds—the flow of blood had slicked and softened the coils of duct tape. It raised its free hand to its face (its slightly pudgy face, now pale and unearthly in its bloodlessness), curled the thumb into a hook and thrust it into the socket of first one and then the other of its eyes.

Once the burning began they couldn’t linger. In the dark, the fire would be visible for miles.

Everything Ethan had wanted to keep—fake ID, a supply of cash and traveler’s checks, a fresh pistol—he had packed into a single cardboard filing box, which he slid it into the backseat of Nerissa’s car. His own car, the secondhand Chrysler he drove into town on weekends, was parked in an outbuilding separate from the house. But it would be smarter to take Nerissa’s car: no one had seen it here and there was nothing to associate it with Ethan or his farm house. He doused the wooden walls of the outbuilding with kerosene and tossed a match behind him. The tindery structure began to burn hastily, and by that time the farm house was already well along, flames creeping up from the foundation and licking out of the first-floor windows. Ethan hurried to the car: he wanted to be gone before the ammunition in the attic began to cook off.