He found an electric screwdriver, but the cold had long ago killed the battery, so he had to turn it manually. When he got the first screw loosened he moved on to the next, and I took over with my cold, clumsy hands, turning each screw the rest of the way, tugging them out and leaving them to drift. When all four had been loosened, Malachi tried to jam the screwdriver head into the seam, but it was too wide. He cursed in frustration. Every breath he sucked in was shallow and desperate.

I searched through the tools again, looking for something thin enough to pry, wasting precious seconds before I remembered Dr. Summers’s pocketknife. I kicked up to her to retrieve it, kicked down again, and snapped it open. I sliced my palm in my hurry, but the quick-hot sting was only a small pain among so many other agonies. I jammed the short blade into the seam, as careful as I could be, terrified of breaking the thin little blade.

It took only the slightest nudge. The pressure on the other side of the panel was still normal; that air was pressing into our suffocating chamber. The seal broke and the panel lifted.

Beneath the panel there were only wires, tubes, and a red handle with no label.

“What do we do?” I said in the brief silence between sirens.

There was no answer. Malachi’s eyes were open, but he was staring blankly, unseeing, his entire body shuddering with useless breaths. I reached for the red handle and tugged. After a few wasteful, fruitless, angry pulls, I realized it rotated. It was a manual crank.

I turned the handle as fast as I could. My grip was slick with the blood from where I had cut myself, and at first nothing seemed to be happening—then I felt a warm breeze flowing upward from the control compartment.

There was a gasp—not me, not Malachi, but mechanical—and a larger panel began to sink into the floor. Rushing air hissed all around it, shoving through the gaps and flowing over my blood-slick hand, warmer than the air around us. I wanted nothing more than to lean my face down to that tiny crack and suck at it, but I didn’t stop. I turned the crank until the floor panel dropped and moved to the side, centimeter by centimeter, at first moving so slowly I could scarcely see it change, then in great gaps—my mind was stuttering, blacking out and snapping to—and a hole opened. The space beneath the floor was dark.

“Malachi,” I said. His eyes were still open, but he didn’t react. “Malachi! We can get out!”