He kneeled down and opened both suitcases; one was full of tools, the other one, the heavy one, contained a stumpy, silvery steel cylinder about a foot in diameter and two feet long. That’s what he’d been working on in his room, apparently—Quentin had seen it in pieces, but never put together. It had a white enamel clock face on one end and a cluster of small wheels and dials on the other. Stoppard unfolded a spindly stand and placed the cylinder on it, then opened the steel case and started fiddling.

Lionel wandered off; he was wearing only a black sweatshirt, the same one he’d been wearing that night in the bookstore, but he didn’t seem to feel the cold. At least they had a big bastard on their side. Betsy began a stretching routine.

“I feel like we should be doing something,” Plum said.

“I wish I smoked. Do you want to go through the spells again?”

“Not really. You?”

“I would but I think my head would fall off.”

So they sat down cross-legged on the carpet in the cold and waited. Quentin could feel Mayakovsky’s coins in his pants pocket. They felt good. They felt like confidence. Stoppard took out a small metal crank, fitted one end into a socket on the back of the machine, and began furiously turning it.

“Mainspring,” he said happily, over the ratcheting sound. His breath puffed out white. “White alloy. Constant even source of kinetic energy. Tough to mess with magically.”

“What does this thing do?”

“Security mostly. It puts a bubble around us, makes us very hard to see or hear or detect magically. It should also keep us warm, which I personally can’t wait for.”

Quentin realized Stoppard didn’t know even basic personal warmth spells, so he cast a few on him as he cranked the mainspring. The bird watched it all. If it was anxious or impatient, there was no way to tell.

Once the machine had been ticking for a few minutes Stoppard detached the handle and stowed it away. He made a couple of adjustments, and there was a soft whirring sound, a hummingbird’s wings against a window, and the hands on the dials began to move. It chimed twice, clearly and musically, and light flashed deep in its gleaming innards like lightning inside a thundercloud.

The wind died around them. There were no other perceptible effects, but Stoppard looked satisfied. He shut the case. Lionel wandered over, frowned, and nodded.

“Good,” Lionel said. “Everybody on. Pushkar, take us up.”