Gretchen took off her white nurse’s cap and ran her hands over her blond hair. “How sweet,” she said. She motioned for him to come closer. He walked a few steps and stopped, and she crossed the room to him. Bits of dust and cobwebs clung to her hair and the shoulders of her cape. But her face gleamed with excitement.

“How would you like to catch the man who killed Lisa Watson?” she asked him.

Archie looked at her uncertainly. There was no smirk, no sarcastic glint in her eye. “I’m not convinced that you didn’t kill Lisa Watson,” Archie said.

Gretchen lifted an eyebrow. “Please,” she said. “Really?”

Archie had assumed she’d brought him here because she knew about the tunnels, and thought the police wouldn’t return after serving the search warrant. But maybe that hadn’t been it at all.

Gretchen’s eyes were bright. “I saw him.”

“You saw him?” Archie repeated. He had no idea what she was playing at.

Gretchen nodded. “That night, at the party, I saw him pick her out.”

Archie rubbed at the concrete grit in his eyes. She was good. He had to hand it to her. She had him. He needed to know more. Even if there was only a tiny chance that she was telling the truth, he had to pursue it. “Tell me,” Archie said with a sigh.

Gretchen moved a little closer to him, radiant in her delight. “I noticed the way he moved through the party,” she said. “He was looking for someone. As soon as he saw her, he started following her. I was intrigued. I knew he was going to kill her.”

“But you didn’t try to stop it,” Archie asked.

“It wasn’t any of my business,” Gretchen said. “But when he put her in the water, I fished her out for you.” Her eyes were keen and penetrating, a teasing smile on her lips. “I know how you like dead girls.”

Archie swallowed hard, uneasy with her closeness, feeling the itch of their proximity. He slid his hand in his pocket and folded his fingers around the pill bottle, his knuckles pressing against his thigh. “What did he look like?” Archie asked.

“Like you,” Gretchen said. “Like everyone that night. He was wearing a tuxedo and a black mask. But I think I can limit the pool of suspects.” She looked at him eagerly, waiting. But he didn’t know where she was headed and could only meet her gaze with a blank look. “He killed her on the island,” she said, leading him, “but there’s no footage?”