Susan scratched her ear. “Oh,” she said.

Archie concentrated on what was in front of him. The hole in his belly stung now every time he took a step. He kept his back to Gretchen and moved along the walls, studying the blood spatter. An open cardboard box in the corner was full of chains. They looked roughly the same size as the ligature marks on Lisa Watson’s torso. Propped against the box were three unopened packages of five-pound scuba-diving weights and a neat stack of black mesh bags. The weights went in the bag, the chain threaded through the bag’s handle, and you’d have a nice anchor for a corpse. The killer had stocked up. He had enough supplies to dispose of several more people before he’d have to go back to the dive store. A black nylon reusable grocery bag sat on the other side of the box. Archie nudged it open with his foot.

“What is it?” Susan asked.

“Lightbulbs,” Archie said. He glanced up at the single bulb that illuminated the room overhead. It would be inconvenient if it burned out in the middle of a murder. The killer had thought of everything.

Archie surveyed the rest of the room.

When his eyes returned to Susan he saw that she was staring at the bloodstain on his shirt. “I’m fine,” he said quickly.

“It’s real?” Susan said. “I thought it was fake.” She glanced at Gretchen. “From touching her.”

Gretchen laughed. “Don’t fret, pigeon,” she said. “Archie doesn’t feel like himself if he’s not bleeding just a little bit.”

The room went dark. It was sudden and complete, a blind, enveloping nothingness. Susan cried out.

“Gretchen?” Archie called, frozen.

She didn’t respond. Susan hiccupped.

“Get on the floor,” Archie said to Susan. He didn’t know what was happening, but whatever it was, he wanted Susan out of the line of fire. The hinges on the door creaked. “Gretchen?” Archie called again into the black. “I’m coming toward the door,” he said. He stumbled forward in the dark, hands groping the air in front of him. As he made his way to the door, he half expected to feel the plunge of a blade into his flesh.

But then his hand touched concrete. He’d made it across the room. He fumbled along the wall until his fingers found the light switch.

He turned it on and light filled the room again. Archie glanced back at Susan, who was looking up at him from where she’d dropped to the floor. They didn’t speak. The room was deathly quiet, but Archie could just make out something on the edge of the silence. He listened carefully, craning his head toward the door. The noise was growing louder, more distinct. It was the sound of footsteps approaching. Gretchen was coming back.