“You want to dance, Hercule?”

Hercule was feeling nervous. The fine cloth of David’s shirt was soft and fitting. She could sense what it would be like to put her hands against his chest, to work them around to his back, to press against his body.

“Maybe a s’more,” she said.

He gestured for her to lead the way.

They stepped back into the main hall, where the less dance-inclined of the Ellingham student body were playing some games. There was another table of snacks out here, and David walked over to it and grabbed a few sticky balls of pretzel and marshmallow.

“A tunnel,” he said, taking a bite. “I’d know.”

This was safer, steadier ground.

“You don’t know everything about the tunnels.”

“I would know that if it was in the floor of the building I live in.”

He sat down in a crepuscular spot under the shadow of the grand stairs. A person dressed as a skeleton bopped by.

“If they wanted to have a real Halloween party, they’d let us into the basement,” she said. “It’s nuts down there. It’s like a maze.”

“Now you interest me,” David said, straightening. “How does one get to this basement?”

“No,” she said. “I promised Larry.”

“A promise is only . . .”

“I promised Larry,” she said, casting her eye in the direction of the doorway to the kitchen.

“Well, this is fun. Sitting on a bench.”

“Then go dance or something,” Stevie said.

“You don’t want to dance.”

“You don’t need my permission,” she said.

“But maybe I’d rather stay with you,” he said.

David stretched out his legs a bit and tapped gently at the inside of her ankle with the toe of his shoe. He turned his eyes up to her. What was this? Flirting? Flirting was sending an unexpected text message. This was something else, something that made her feel like she did when Ellie gave her that warm champagne to drink on the first day—bubbles in the bloodstream, an air of unreality. No. This was more than that. This was like she’d gone through a stargate into the life of some parallel universe Stevie. She was used to feelings that butted up against each other, the way that anxiety brought bad excitement. She could handle that now because she knew that feeling. This was something like good nausea, which made no sense, and therefore she was back to anxiety and its bad excitement, except there was a new chemical level.

And in this case, because everything stunk of Edward King, no good move to make. There were no answers here, except to avoid, avoid, avoid.

She tried to look away from his tapping foot and concentrated on the stairs sweeping above them, and the door to the kitchen underneath. The door to the kitchen under the stairs. A lot happened under staircases in old houses. Under the stairs, that’s where the servants worked. Harry Potter lived under the stairs. Even Albert Ellingham had written about something being under the stairs. “Where do you look for someone who’s never really there? Always on a staircase . . .”

“But never on a stair,” she said out loud.

“Come again?”

Stevie was already on her feet, and David followed. As they passed the door, Call Me Charlie Chaplin regarded them with confusion.

“Going so soon?” he said.

“I forgot something,” Stevie replied. “My . . . medication. Have to take it. Be right back.”

Charlie Chaplin tipped his bowler hat. Stevie and David—or Hercule and Sherlock—walked double-time down the path and under the trees, quickly enough that Stevie worked up a cold sweat.

“So what’s happening now?” he said.

“Under the stairs,” she said. “Did you ever look under the stairs? In Minerva?”

“Meaning what?”

“The stairs are enclosed, but there has to be space under there. It’s the only place you can’t see and wouldn’t be likely to look.”

“Under the stairs,” he repeated. “What made you think of that?”

“I just did,” she said. As they hurried, she noted that they were passing by one of the cameras, the dark glass and the little blue pinpoint of light recording their movements. Maybe Edward King watched these, maybe he saw this now—Stevie and David together. He would approve. Here Stevie was, doing his bidding. She wasn’t even in control of it anymore.

Inside of her jacket pocket, she gave the camera the finger.

Back in Minerva, she and David went right to the stairs, those creaky beasts that would always remind her of Hayes on that first day, when he got her to carry his stuff. On that day, the light poured in through the stained glass. She walked behind him, staring at his muscular calves, covered in light-colored hair, as she hauled a box. He was talking about Hollywood and his show. That was only about two months in the past. Now his death was a memory.

Tonight, the hall was dark. There were lights, but they did little to illuminate the end of the hall. Maybe this was intentional, she thought—keep the attention off the stairs, make details harder to see. The stairs were a tight coil, and underneath was a curved bit of wood that met up with the wall. She felt the wood, running her hands up and down to feel for any openings. David knocked on it.

“Sounds kind of hollow,” he said. “I guess I never thought to go and beat on the stairs before.”

She knocked as well. There was definitely empty space behind. It was entirely possible that there would be nothing at all behind this structure, just dust and air, but her heart was thumping and her brain felt clear.

While she had a flashlight on her phone, she needed something more. It was time to employ the tactical flashlights that the school issued to every student in case of power outage. She went to her room and got hers. These were no simple cylindrical flashlights that gave you a gentle beam—these were monsters with handles that blinded and confused the enemy and summoned passing planes. Stevie took hers into the hall and switched it on. Suddenly, the end of the hall was flooded in a white light that exposed detail.

“Hold it,” she said, shoving it into David’s hands.

Bathed in clinical illumination, the staircase began to offer up its secrets. While the surface appeared smooth, she could just make out the finest trace of a doorway. It had been expertly fitted to be virtually invisible. The 1930s had not anticipated this kind of luminosity.

“Hello,” she said.

“Holy shit,” David added.

There was no visible way of opening the door, and the opening was no wider than the edge of a piece of paper, possibly even more narrow. There had to be a catch somewhere, something that would pop it. Stevie felt all along the floor, the walls. Nothing.

“In movies you pull down a candlestick on the wall,” David said as he set the flashlight on the floor. He took off his two-thousand-dollar coat and bunched it up to make a wedge to prop the light toward the wall.

“This isn’t a movie. We don’t have a candlestick.”

David came over to help her feel the wall. He examined the steps, running his fingers under the lip of each one.

“Why are you fondling the wall?”

They had not heard Nate return and slink up to them in his wizard robes.

“Do you really want to know?” Stevie said.

“Oh God.”

“Then I’d turn around,” she said. “You won’t like it.”

“I don’t like anything. What are you doing?”

“Looking for a tunnel,” she said.

Nate looked at Stevie with an expression that said, Make this stop happening.

“It won’t be like last time,” Stevie said. “This is just for research.”

“So was the last time. You guys . . .”

“Wait,” David said. “Back up, back up.”

He motioned Stevie to clear, then took a step back and threw himself against the wood, hard. Nothing. He backed up a step and rubbed his arm.

“Good one,” Nate said. “Keep doing that.”

“I thought I felt something,” David said. “Let me . . .”

He threw himself up against the wood again, letting out a little groan as he made impact.

“Yeah,” Stevie said. “Maybe . . .”

One more time. And this time, there was a pop. Just a small pop.

The panel had shifted, just the tiniest bit, and now there was an opening about a quarter of an inch wide.

“Cool,” Nate said. “Just slip on through there.”

“Screwdriver,” Stevie said.

She did not have one, but Janelle certainly would, and Janelle usually left her door unlocked. It was wrong, of course, to go in, but this was an emergency. Janelle’s room was an expression of its inhabitant—perfectly organized, every bit of space cared for and optimized. The air smelled of perfume and honeysuckle from a scented oil diffuser. Her workstation was by the window. She had repurposed her desk and put all her tools there. After a moment of looking through clippers and more confusing devices, Stevie found a small hammer. That would do.