“I’m not actually sure how we’re going to do that. You’re supposed to come in through the fountains, but you need a button to do that.”

“Okay.” Their voices vanished in the frozen air as soon as they spoke. “Well, but do a spell or something. Why did it take us here?”

“I don’t know. They’ve got a sense of humor, those keys.” It was hard to think in the bitter cold. He studied the empty air they’d just appeared out of, his breath smoking. There was really nothing left of the portal back to Fillory. Poppy walked stiff-legged over to the fountain. They were in the Fillory square; the fountain had a statue of Atlas in it, coiled and braced under the crushing weight of a marble globe.

The water in the fountain was frozen. The level of the ice was actually above the stone rim. She felt it with her hand.

“What the shit,” she said quietly. She didn’t sound like herself.

It was dawning on Quentin how much trouble they were in. It was cold here, really cold. It couldn’t have been more than 15 or 20 degrees. There was no wood, nothing to make a fire with, nothing but stone. Quentin remembered Penny’s warning not to do magic here. They might have to test that.

“Let’s go over to the Earth fountain,” he said. “It’s a couple of squares from here.”

“Why? What good would it do if we don’t have a button?”

“I don’t know. Maybe there’s somebody there. I don’t know what else to do, and we have to start moving or we’re going to freeze to death.”

Poppy nodded and sniffed. Her nose was running. She looked more frightened now than she had back on the island, when they were fighting for the key.

They started to walk but immediately broke into a jog instead, to warm up. Apart from their footsteps the silence was absolute. The only light was starlight, but their eyes were adjusting rapidly. All Quentin could think was that this wasn’t going to work, and after it didn’t work things would get very bad. He tried to do mental calculations about thermodynamics. There were too many variables, but hypothermia wasn’t far in their future. A few hours at most, maybe not even that.

They trotted through the broken cityscape. Nothing moved. They crossed a bridge over a frozen canal. The air smelled like snow. A stupid mistake, and now they were both dead, he thought giddily.

The Earth square was bigger than the Fillory one, but it was in no better shape. One of the buildings showed a row of empty windows through which the stars were visible. The façade had survived the catastrophe, but the building behind it was gone.