“I’m a pretty, pretty girl,” Stevie said. “Who likes to be comfortable.”

Vi had also noticed Stevie’s presence, and was dragging Janelle across the room. Vi was properly dressed up in a dress shirt and yellow tie with white dots. Janelle had on a yellow skirt and a white blouse. Matching outfits to a dance. It was beyond anything Stevie could understand, but it was so right for them.

“Hey!” Vi said with a bit of forced cheerfulness. “Everyone’s here!”

Janelle looked down at the floor for a moment.

“Yeah,” Stevie said. “I wanted to hang out. We wanted to hang out.”

“I live to dance,” Nate said.

“So, let’s dance,” Vi said.

Stevie did not actually know how to dance. This seemed like information other people were born with, something that was as natural as walking. It was very puzzling to her how people managed to just pick it up. But Janelle wanted her to dance, and Nate had brought her to this dance, and right now she had to observe at a dance . . . so that meant she was going to dance. She tried the knee-bending thing first, but even Nate looked at her with pity. So she tried employing her arms instead, windmilling them like Ellie across the room.

How this looked to David, who was standing there watching, was unclear. It didn’t matter. There was nothing left to lose.

Janelle burst into uncontrollable laughter and had to lean on Vi for support. Then she wrapped her arms around Stevie’s neck.

“You are ridiculous,” she said.

“I know,” Stevie said.

Janelle and Vi swung back into each other’s arms and started dancing more slowly. Stevie looked at David, but he had already turned and made his way back to the wall. She ignored the ache this caused.

At the end of so many Agatha Christie books, Poirot would gather the suspects to look at them. If Ellingham was gathered in one room tonight, then she could examine everyone at once. Look for someone who would have reason to put that dry ice in that tunnel and never come forward. Look for the reason Hayes turned around.

She rotated, taking in this room decorated in honor of masks and mischief. Commedia players on the wallpaper and masks supporting the lights. Everything was a trick with mirrors, making the room repeat.

Where do you look for someone who’s never really there. . . .

Albert Ellingham wanted her to think.

Was it Gretchen? Gretchen, who openly confessed to doing Hayes’s work for him, to being furious? Gretchen who was owed five hundred dollars?

“Come on!”

Janelle had come up behind her and taken her hand. She started to dance with Stevie again. Stevie tried to keep up, moving as best she could. It was good to see Janelle smiling at her, at least, and Vi gave a little nod of, It’ll be okay.

Maybe this was enough. Just to be with her friends. Be a normal girl. Stop thinking you found a murder. Close your eyes and dance.

Janelle squeezed Stevie’s hand gently, putting just a little pressure on the scratch she’d gotten earlier.

Something shot through Stevie’s brain.

Her hand. Something about her hand. A pain in her hand. A scratch. She put her attention there, on the back of her hand, focusing it like a soft spotlight. The hand would speak to her. The hand would tell its story if she let it.

Her hand cycled through its memories. The cold that rubbed the skin dry. The warmth of the inside of her fleece pockets. The feeling of David’s skin . . .

“Be right back,” she said. “I have to . . . go to the bathroom.”

The music changed and everyone began to move more frantically. Stevie knocked the headphones off her ears and craned her neck to look around. There was one person she needed to see, one person who was always there whether you noticed her or not. And she was there, of course, sitting on one of the low benches by the windows, working her phone. Stevie made her way over.

“I need to see your pictures from the day in the garden,” she said.

Germaine peered at her curiously.

“Why?”

“Because I do, Germaine,” she said. “Please. I’ll owe you. Please.”

“I like I’ll owe you,” Germaine said. She flicked through her phone for a moment and then held it toward Stevie. Stevie swiped until she found what she hoped was there—a clear shot of Hayes sitting and acting like he was working on his laptop. She zoomed in.

Her heart thudded.

“Hey,” Nate said, coming up behind her.

“Wait,” Stevie said. “Wait a second.”

The three of them stood in their puddle of silence as everyone gyrated around them.

Stevie pulled up her own pictures of Hayes’s room. The fan-art wall, the bureau, the desk, the computer . . .

She swore under her breath in a continuous stream.

In Germaine’s pictures from Saturday, Hayes’s computer was scratch free. But when it appeared again in Stevie’s photos from her room search after his death, there were three clear marks down the front, like the claw marks of a cat. They were three marks she had seen before on her own hand, when she reached under the tub on that first day.

“What’s happening?” Germaine said, watching Stevie’s face closely.

Someone had taken Hayes’s computer and hidden it under the tub.

Why would you do that?

Think, Stevie.

If you needed to look for something, maybe evidence that you had written a show that Hayes was taking credit for, a show that was going to be a movie. Maybe you did something to mess with him. Maybe you killed him by accident. And then maybe you had to cover your tracks afterward. Make sure there was nothing on his computer identifying you as the true author.

Janelle and Nate could be eliminated. They were not at Ellingham last year. That left Ellie and David.

It had come down to this.

Ellie, who loved art and went to Paris and got tattoos. Ellie who was funny and careless and maybe tried much too hard. David, who lied. David, whose parents were dead. David, who held everything in. David, who messed with people.

The lights in the room flashed pink and pulsed, like rose-colored fingers reaching for the ceiling. The eyes of the masks glowed.

Either one of them was capable of getting out at night. As for Hayes’s fingerprints on the ID? Simple. You just gave it to him to hold.

Intent. Planning. Maybe the goal was just to get him kicked out and everything went wrong.

Of the two, David should have known better. He studied more math and science. David would likely have had a better sense of what that much carbon dioxide might do. Ellie, on the other hand, might have liked the idea of the artful cloud of fog.

Could it really all come down to a few scrapes on a computer?

“What is going on?” Nate said.

“I’m still working that out,” Stevie said.

“Let’s just talk to Larry right now,” he said. “Let him get the police.”

“The police didn’t get this far,” she said. “I got this far. And I can get the rest of the way.”

“Don’t say things like that,” Nate replied. “It makes me feel like you’re about to get us both killed or something.”

“No,” she said. “We just have to go home.”

The dance ended at midnight. Stevie watched to make sure all her Minerva people were in sight. Janelle and Nate were by her side. Ellie and David walked ahead of them. David occasionally turned around to look at Stevie curiously.