Several Alchemists sat in little booths with their backs to me, facing dark monitors and wearing headphones. Large microphones were embedded in their desks along with a control panel I couldn’t read. This was where the solitary prisoners were monitored, I realized. Each prisoner must always have a watcher, with that microphone masking their voice and the panel allowing control of the gas and lights. I’d suspected they rotated personnel, and here was my proof. I hadn’t had time to get a full count, especially with part of the room blocked from my view, but I’d seen at least five watchers.

What I had also seen, with absolutely clarity, was an exit sign. It had been on the far side of the room, past the watchers and monitors, but there’d been no mistaking those glowing red letters. My heart rate sped up. This was it, the way in and out! For a few seconds, I wondered how easy it would be to slip in and stroll right out of this place. Not that easy, I soon admitted. For one thing, this wasn’t a simple room to infiltrate. Those doors didn’t allow for darting in and out, and they made enough noise when opened that someone would likely notice them opening by themselves. Even with no Alchemist directly monitoring them, some personnel were sitting far too close for my comfort.

There was also the likely fact that no one could just “walk out” of that exit. I wouldn’t have been surprised if there were real guards, more card readers, and probably numerical codes for exit and entry. The Alchemists had already set up a considerable fire hazard in having so few exits to begin with. If they felt so strongly about prisoner security that they were willing to take that risk, they certainly weren’t going to leave that exit exposed.

Still, it was hard to walk away from that door, knowing what lay beyond it. Soon, I told myself. Soon. A further scan of the hall revealed nothing else of note, and I headed back toward the stairwell. As I did, its door opened, and Sheridan stepped out. I immediately flattened myself against the wall, averting my eyes downward. In my periphery, I could see her pause as though she were searching for something, and then she began walking again. When she was past me, I lifted my head and watched as she continued down the corridor, almost at a leisurely pace. At last, she reached the end, stood there a few moments, and then doubled back to the control room doors, which she soon disappeared through. I hurried into the stairwell before she came back, taking the last option left to me: down to the last level.

The elevators went no farther than this level, and the stairs ended here as well. This was the only level I’d never been on, and I couldn’t imagine what happened down here. What else was there for them to do? The doors I found offered no answer. They looked identical to the reflection time ones, and I almost wondered if I’d simply found another set of solitary cells. These were labeled with the letter P and numbers, however, and I found no corresponding control room to illuminate what that letter stood for. What I did find were three doors labeled MECHANICAL 1, MECHANICAL 2, and MECHANICAL 3. Behind them, I could hear the buzz of generators and other equipment. They had no card readers but did require an old-fashioned mechanical key.

Racking my brain, I recalled a key spell I’d once copied for Ms. Terwilliger, one that would open an ordinary lock. I murmured the Latin words, calling on the magic within me, hoping there was nothing too unusual about this lock. Power surged through me, and a moment later, I heard a click. Dizziness briefly swept me, and I ignored it as I began my exploration, unlocking the other doors as needed.

The first door revealed a room with a furnace and other HVAC equipment but nothing like what I expected for gas controls. The second room was where I struck gold. Along with a generator and some plumbing systems, I discovered an enormous tank labeled with a chemical formula that read very much like a sedative to me. Four pipes fed off it, each one labeled with a floor number. Each also had a manual valve that could be adjusted. All of them were currently in the “on” position.

I saw no sign that there was any sort of sensor to alert tampering at this level. Taking a chance, I turned the valve for the detainee floor to “off.” No alarms or lights went off. Emboldened, I nearly considered turning off the others but then realized I’d be exposing what I’d done. Maybe there were no sensors here, but the Alchemists would immediately notice if the gas was shut off on the level with the solitary cells. They controlled the gas there manually and were able to observe instant results. Turning off the gas on the detainee level would affect sleep right now, and that wouldn’t be readily obvious to the Alchemists. It might not even be noticeable to the detainees. They didn’t let us get eight hours of sleep anyway; it was unlikely anyone had much trouble falling asleep at night.

It was a hard call to make, abandoning the prisoners in reflection time, but there was nothing I could do for them right now. The status quo had to go on for them, and I needed that gas off on my floor as long as I could manage. Judging from the tank size, it probably went a while between refills, but eventually someone would come for a maintenance run and discover the valve. That was the timeline I had to worry about.

In the same room, I discovered another tank with a chemical formula I wasn’t entirely sure of, but I was betting it was a different substance, one I’d occasionally felt in my cell that made me agitated and paranoid. They didn’t employ it with the same regularity as the sedative, but I turned this valve off for my floor too, just in case. We didn’t need any extra incentive to be suspicious of one another.

With that work done, I hurried out and ignored my curiosity about the third mechanical room and P-marked doors. I’d achieved my goal tonight and needed to get back to my room before my spell wore off. That, and I knew Adrian would worry if I was very late. I took the stairs back up to the detainee living level and peered out the door’s window before opening it. No one was visible. I opened it a crack, so as not to attract attention on cameras, and squeezed my way out . . .