As Rector climbed up the last set of stairs (he hoped), he watched the other boy slip the mask over his face with the practiced ease of someone who did this a dozen times a day, every day. With somewhat more difficulty, Rector put his on, then went over the threshold, joining Houjin outside the vaults.

The scenery wasn’t terribly interesting—there was just a dark roof made of earth and reinforced timbers where the sky ought to be. Basement walls and building foundations disappeared upward like ordinary building fronts without windows, and the streets between them were packed and damp. The walkways were littered with barrels and buckets, stones, brooms, tracks, bricks, ladders, bird skeletons, rusting junk, and handwritten signs that advertised directions or left messages.

Houjin scanned those messages, some of which were written in Chinese, and shrugged to indicate that none of them were directed at him. “Let’s go,” he urged, his voice muffled by the filters.

Already, Rector hated the masks. They were uncomfortable and tight, and they made it hard to see and breathe.

Houjin used his foot to shove the door closed once more, locking it with a loud, low clank and pop. He explained, “It’s easier to shut it than push it open. Are you ready?”

“Why wouldn’t I be?” He might’ve been grinning behind that mask, but Rector didn’t like it.

“Your first trip into the city didn’t go so great, that’s all.”

“The second time’s a charm.”

“I thought that was the third time.”

Rector sniffed, and caught a whiff of a sour mixture of charcoal, sweat, and mildewing leather. “Once in a while I get a second chance. I’m never lucky enough for a third.”

Down short, meandering paths and around crumbling corners, he stuck close to Houjin, who knew his way around as if he had a map burned into his brain. Rector tried hard to pay attention, to note his surroundings and let his internal map keep track of them. Sometimes he thought he had a handle on it, but other times he was sure he couldn’t have found his way back to the Vaults without a native scout and a fistful of cash.

“This place is a rabbit warren,” he complained, holding his side. “Hey, can we slow it down a little?”

“Sure. Sorry. We’re almost to the top, anyway. Catch your breath.”

“We’re near the fort?”

Houjin said, “Practically under it. I didn’t want to take you the overhead way. You were griping about the stairs, so I thought this would be easier. One more set, and then a ladder. But that’s all for now, I promise.”

“I’ll hold you to that.”