“The man who killed Lisa Watson the night of the party,” Gretchen said before Archie could answer. “We think he works for Jack Reynolds, and that he’s killed before.”

Archie wished Gretchen would stop talking. He glanced back at her. She was still standing just inside the door. She blew him a kiss.

“We?” Susan said to Archie.

“Gretchen was here that night,” Archie told Susan.

“No shit,” Susan said.

Archie wondered if she would ever be able to look at him without seeing the images from the flash drive footage. “The woman found dead this morning,” Archie continued. “Gretchen didn’t kill her.”

Susan looked skeptical.

“Gretchen saw it,” Archie said. “She witnessed the killer lure Lisa Watson into the tunnels and then later bring up her body and dump it in the lake.”

The lantern on the floor went out. Susan glared accusingly at Gretchen. “That wasn’t even a hundred hours!” she sputtered.

“I didn’t say the batteries were new,” Gretchen said.

Archie tried to ignore them both, and began to scan the room clockwise as if it were any other crime scene, taking in the walls, ceiling, and floor. The mattress, Archie noticed, wasn’t just soaked with blood. It was soaked with generations of blood. Stains overlapped one another, in various stages of oxygenation.

“You can’t believe her story,” Susan said. “She’s a pathological liar.” Susan hiccupped again. “What are you doing?”

Archie had inched closer to the mattress. “I’m looking for clues,” he said.

“I thought you said Gretchen saw him,” Susan said.

“He was wearing a mask,” Gretchen said from the door.

“It must have been a big mask,” Susan muttered.

“I only saw him from a distance, pigeon,” Gretchen said.

Archie could hear the irritation in Gretchen’s voice. If Susan kept goading her, it wouldn’t matter what Archie said or did—Gretchen would kill her. “You were right,” Archie announced to Gretchen. “There are varying ages of bloodstains here.” Archie glanced over at Susan. “He’s killed more than one person in this room.”

“A serial killer, huh?” Susan said. “I know someone else like that.” She pointed at Gretchen. “Her.”

Archie willed Susan to understand what he was trying to do, that he had to go along with this, that he was doing it for her. “If I can stop this guy, I can save lives,” he said.

Susan crossed her arms. “Your judgment hasn’t been exactly stellar lately,” she said. She pursed her lips and lifted her chin. “The stripper?” she said. “For instance?”

Archie cringed.

“What stripper?” Gretchen asked.

“I did not have sex with the stripper,” Archie said to Susan. “Not that I have to explain that.” He looked back at Gretchen. “To either of you.” He turned back to Susan, remembering suddenly how infuriating she could be. “I had to talk to Leo. In private. And I wasn’t drunk, by the way. It was nonalcoholic beer.”