So I sat down on the floor, pulled up my knees, and prepared to wait.

I don’t know when I fell asleep, but I jolted awake at the sound of footsteps on the other side of the door. I jumped up from my spot, the flip-flops I’d pulled off earlier still in my hand, my only weapon. As I faced down the door with only a few inches of green foam as protection, it occurred to me that there might be a stranger—and not Scout—on the other side of the door.

My heart raced hammerlike in my chest, my fingers clenched into the foam of my flip- flops. Suddenly the flywheel began to turn, the spokes rotating clockwise with a metallic scrape as someone sought entrance to the convent basement. Seconds later, oh so slowly, the door began to open, hundreds of pounds of metal rotating toward me.

“Don’t come any closer!” I called out. “I have a weapon.”

Scout’s voice echoed from the other side of the door. “Don’t use it! And get out of the way!”

It wasn’t hard to obey, since I’d been bluffing. I stepped aside, and as soon as the crack in the door was big enough to squeeze through, she slipped through it, chest heaving as she sucked in air.

She muttered a curse and pressed her hands to the door. “I’m going to rail on you in a minute for following me, but in the meantime, help me close this thing!”

Although my head was spinning with ideas about what, exactly, she’d left on the other side of the door, I stepped beside her. With both pairs of hands on the door, arms and legs outstretched, we pushed it closed. The door was as heavy as it was high, and I wondered how she’d gotten it open in the first place.

When the door was shut, Scout spun the flywheel, then reached down to slide the steel bar back into its home. We both jumped back when a crash echoed from the other side, the door shaking on its giant brass hinges in response.

Eyes wide, I stared over at her. “What the hell was that?”

“Litter,” Scout said, staring at the closed door, as if making sure that whatever had been chasing her wasn’t going to breach it.

When the door was still and the hallway was silent, Scout turned and looked at me, her bob of blond hair in shambles around her face, jacket hanging from one shoulder . . . and fury in her expression.

“What in the hell do you think you’re doing down here?” She pushed at the hair from her face, then pulled up the loose shoulder of her jacket.

“Exercising?”

Scout put her hands on her hips, obviously dubious.

“I was afraid you were in trouble.”

“You were nosy,” she countered. “I asked you to trust me on this.”

“Trusting you about a secret liaison is one thing. Trusting you about your safety is something else.” I bobbed my head toward the door. “Call it community improvement if you want, but it seems pretty apparent that you’re involved in something nasty. I’m not going to just stand by and watch you get hurt.”

“You’re not my mother.”

“Nope,” I agreed. “But I’m your new BFF.”

Her expression softened.

“I don’t need all the details,” I said, holding up my hands, “but I am going to need to know what the hell was on the other side of that door.”

As if on cue, a crash sounded again, and the door jumped on its hinges.

“We get it already!” she yelled. “Crawl back into your hole.” She grabbed my arm and began to pull me down the hall and away from the ominous door. “Let’s go.”

I tugged back, and when she dropped my arm, slipped the flip-flops back onto my feet. She was trucking down the hall, and I had to skip to keep up with her. “Is it an axe murderer?”

“Yeah,” she said dryly. “It’s an axe murderer.”

Most of the walk back was quiet. Scout and I didn’t chat much, and both the main building and the Great Hall were dark and empty of students. The moonlight, tinted red and blue, that streamed through the stained glass windows was the only light along the way.

As we moved through the corridors, Scout managed not to look back to see whether the basement door had been breached or whether some nasty thing was on our trail. I, on the other hand, kept stealing glances over my shoulder, afraid to look, but more afraid that something would sneak up behind us if I didn’t. That the corridors were peacefully quiet didn’t stop my imagination, which made shapes in the shadows beneath the desks of the Great Hall when we passed through it.

Exactly what had been behind that door? I decided I couldn’t hold in the question any longer. “Angry drug dealer?” I asked her. “Mental institution escapee? Robot overlord?”

“I’m not aware if robots have taken us over yet.” Her tone was dry.

“Flesh-eating zombie monster?”

“Zombies are a myth.”

“So you say,” I muttered. “Just answer me this: Are you in cahoots with those Montclare guys?”

“What is a ‘cahoot,’ exactly?”

“Scout.”

“I was exercising. Great workout. I got my heart rate up, and I got into the zone.” Her elbow bent, she pumped one arm as if lifting a dumbbell.

When we opened the door to the building that held our dorm rooms, I pulled her to a stop. She didn’t look happy about that.

“You were being chased,” I told her. “Something behind that door was after you, and whatever it was hit the door after we closed it.”

“Just be glad we got the door closed.”