There was no reason to wait. Too much time to consider the ramifications, Peter knew, and his courage could dissolve. He led them to the empty house he had prepared—the last one, at the far end of the trace. It was little more than a shell; nearly all of the interior walls had been removed, leaving the joists exposed. The windows were already boarded up, another reason Peter had selected it—that and the fact that it was farthest away. Hollis took up the ropes Peter had moved from the barn; Michael and Greer carried a mattress from one of the adjacent houses. Somebody had brought the lantern. While Hollis tied the ropes to the joists, Peter stripped to the waist and lay down on his back. He was suddenly very nervous, his awareness of everything around him almost painfully vivid, his heart beating very quickly in his chest. He raised his eyes to Greer. A silent bargain, struck between them: if it comes to that, don’t hesitate.

Hollis finished tying the ropes to his arms and legs, leaving Peter spread-eagled on the floor. The mattress smelled like mice. He took a deep breath, trying to calm himself.

“Sara, do it now.”

She was cradling the box with the virus; in her other hand was one of the syringes, still sealed in plastic. Peter could see that her hands were trembling.

“You can do this.”

She passed the box to Michael. “Please,” she begged.

“What am I supposed to do with this?” He held the box away from his body, trying to give it back. “You’re the nurse.”

Peter felt a blast of exasperation. Any longer, and his resolve would fail him. “Will somebody, please, just get this done.”

“I’ll do it,” Alicia said.

She took the box from Michael, and opened it.

“Peter … ”

“What is it now? Flyers, Lish.”

She turned it in her hands to show them. “This box is empty.”

Amy, he thought. Amy, what have you done?

They found her kneeling by the fire pit as she was dropping the last vial into the flames. Baby Caleb lay against her shoulder, wrapped in a blanket. A sizzling pop flew up as the liquid inside the last vial expanded to a boil, shattering the glass.

Peter crouched on the ground beside her. He was too stunned even to feel angry. He didn’t know what he felt at all. “Why, Amy?”

She did not look at him but kept her eyes focused on the fire, as if to verify that the virus was really gone. With the fingers of her free hand she was gently stroking the baby’s cap of dark hair.

“Sara was right,” she said finally. “It was the only way to make sure.”