No footage. Archie’s hand was sweating; the plastic pill bottle slipped from his fist. There were cameras all over that island. Gretchen was right. If Lisa Watson had been killed on the island, then the killer had managed to avoid a blanket of surveillance. “He knew where the cameras were,” Archie said. Gretchen was staring at him, nodding as Archie pieced it together. “It’s someone who works here,” he said.

Gretchen grinned widely, threaded a piece of hair behind her ear, and leaned forward to put her bare cheek next to his. The edge of her cape brushed against his leg. His fingers circled the round cap of the pill bottle. “There’s more,” she whispered.

Acid rose in Archie’s throat. “You befriended her,” he said, finally understanding. “When you saw her being stalked, you wanted to be close to her, to see what would happen.” The girl in the bathroom. Ronin had been right. Lisa Watson had come alone. Gretchen had been on the other side of that door. “That was you.”

Gretchen’s face glowed with pleasure. “You almost spotted me,” she said. “I saw you come inside the house and I only barely managed to dive into the bathroom in time.” She shrugged. “When I came out, both you and Lisa were gone. I raced to the back door and I saw him leading her away. I followed them. He whispered in her ear the whole way. He stayed off the paths. Out of view of the cameras. I followed in his footsteps. He took her to the boathouse. Into this old tunnel system,” she said. “She went willingly,” she added. “Probably excited to see Al Capone’s vault or something.” Gretchen cocked her head and Archie thought he saw something like admiration in her eyes. “It was a good place to kill her. I didn’t hear any screaming. He took his time with her. He didn’t bring the body up until it was nearly dawn.”

Archie stared at her, desperate for how to respond, his mind racing. He had spent half the night unconscious near the boathouse. Had he been twenty feet away while a girl had been murdered? Had he laid there with a hard-on while some girl was tortured to death? He rubbed his face with his hands, the idea of it almost too awful to contemplate. “At what point did you take me down there?” he asked Gretchen.

Her eyes widened in surprise. “I didn’t take you there. You don’t remember? You made it out of the house all on your own. He was already in the passage with the girl when you came wandering down the stairs bleeding. I helped you lie down so you wouldn’t fall in the pool and drown.” She touched a button on his shirt. “I was taking care of you, darling. I put you someplace where I knew he wouldn’t see you.”