She could see nothing in the ink-dark hole under her feet, but between the enormous gasping breaths of the tube she heard machinery grumbling and large metal parts clicking together.

The air came and went with whistling moans, inhaling and exhaling Briar’s hair, her coat, her satchel. Her hat trailed above her head like a balloon, anchored by the ties that fastened it under her chin, over the mask.

She couldn’t stand there forever, but she couldn’t see where a farther fall might bring her. A series of clanks like the fastening and rolling of huge gears sounded in time with the breathing: close, but not dangerously close, she didn’t think. And at that point, all danger was relative.

On the air current’s intake stroke, she scooted one foot away from the rim and braced her back against the tube. Her foot felt around, examining the darkness by touch. She found nothing, so she lowered herself a bit more. Her arms strained against her body’s weight, even when the air tube’s outtake gasp tried to lift and expel her.

She let herself down another few inches, until she was hanging with her shoulders and chest level with the last sturdy rib, the toe-points of her boots dangling down over nothing, and finding nothing. By now she could reach the more substantial rib with her fingertips, so she unlocked her elbows and let herself droop down a few inches more.

There.

Her feet scraped against something soft. The investigating motion of her swinging boots pushed it aside, only to land again on something else soft and small. Whatever she was fondling with the bottoms of her feet, it was resting on something firm, and that knowledge was enough to let her exhausted hands release their grip.

She fell, only briefly, and landed on all fours.

Under her hands and knees, small things broke with a hundred muffled snaps, and when the air tube exhaled again, she felt light fluttering bits of debris rise into her hair. They were birds, dead ones—some of them long dead, or so she guessed from the brittle beaks and decayed, dismembered wings that flapped with the shifting air. She was deeply glad she couldn’t see.

Briar wondered why the birds didn’t explode out through the tube every time the air flow shifted, but by exploring with her hands and feeling the gusting gasps, she thought that perhaps they had only collected there, out of reach of the tube’s main drawing and exhaling force. This was confirmed when she tried to rise and knocked her head against a ledge.

Her stopping place was only a shielded corner where detritus could accumulate. She held out her hands, crouched to keep from hitting her head again, and searched for the chamber’s boundaries.

Her fingertips stopped against a wall. When she pressed against this wall it gave a little, and she realized it wasn’t made of brick or stone. It was thicker than canvas, more like leather. Perhaps it was fashioned from several layers fused together—she couldn’t tell. But she leaned on it, and continued searching with her hands, up and down, seeking a seam or a latch.

Finding nothing of the sort, she pressed her head against the barrier and was almost certain she heard voices. The wall was too thick or the sound too distant for her to gather a language or any distinct words, but yes, there were voices.

She told herself that it was a good sign, that yes, there were people there inside the city and they lived just fine—so why not Zeke, too?

But she couldn’t bring herself to knock or cry out, not yet. So she held her ground, littered as it was with the corpses of long-dead winged things, and strained to learn more about whatever might wait on the other side. She couldn’t stay there in the feathered graveyard forever. She couldn’t pretend that she was safe. So she had to act.

At least she’d be out of the dark.

She balled her hands into fists and struck at the dense, slightly pliable wall. “Hello?” she yelled. “Hello, can anyone hear me? Is there anyone out there? Hello? Hello—I’m stuck inside this… thing. Is there any way out?”

Before long, the grinding apparatus of the inhaling, exhaling machine slowed and stopped, and then Briar could hear the voices better. Someone had heard her, and there was excited chattering on the other side of the wall, but she couldn’t tell if the chatterers were angered, or pleased, or confused, or frightened.

She smacked her fists on the barrier again and again, and she continued her loud, insistent plea until a line of light cracked to life behind her. She swiveled, crushing a small carcass underfoot, and held her hand up to her mask. Narrow though it was, the ribbon of white seared her eyes as if it were the sun.

The silhouette of a nearly naked head was outlined and backlit.

A man’s voice rattled something hurriedly, and incomprehensibly. He waved his hand at Briar, urging her to come out, come out. Come out of the hole where the dead birds gather.

She stumbled forward, toward him, her arms extended. “Help me,” she said without shouting. “Thank you, yes. Just get me out of here.”

He seized her hand and pulled her out into the light of a room filled with carefully controlled fires. She blinked and squinted against the sudden brightness of coals and a haze of smoke or steam, turning her head left and right, trying to see all the corners that the mask cut off from her vision.

Behind her and to the left, there was a huge set of bellows—a giant’s version of what might sit beside an ordinary fireplace. The bellows were attached to an elaborate machine with gears that had teeth as big as apples; and there was a crank to move the gears, presumably to pump the bellows. But the crank itself was folded against the side of the machine, resting there as if it were only a secondary means of moving the device.

Off to the side, a massive coal furnace with a smoldering-hot interior seemed the more likely power source. Its door was open, and a man with a shovel stood beside it. Four tubes of assorted materials and designs came and went from the mighty bellows: the yellow slide through which Briar had descended, a metal cylinder that connected to the furnace, a blue cloth tube that disappeared into another room, and a gray one—once perhaps white—that vanished back into the ceiling.

All around Briar the voices asked questions in a language she didn’t speak, and from every direction hands squeezed at her, touching her arms and her back. It felt like a dozen men, but it was only three or four.

They were Asian—Chinese, she guessed, since two of the men had partially shaved heads with braids like Fang’s. Covered with sweat, wearing long leather aprons that protected their legs and bare chests, the men wore goggles with tinted lenses to shield their eyes from the fires they worked.

Briar tore herself away from the men and retreated into the nearest corner that did not hold a furnace or an open bowl of flame.

The men advanced, still speaking to her in that tongue she could not decipher, and Briar remembered she had a rifle. She whipped it off her back and aimed it at the first man, and the next one, and the third—back and forth—and at the next two men who entered the room to see what the commotion was about.

Even through the charcoal filter in her mask, she could sense the soot choking the air. It smothered her, even though it couldn’t really be smothering her, could it? And it watered her eyes, though it couldn’t really reach them.

It was too much, too sudden—the masked and chattering men with their fires and their shovels, their gears and their buckets of coal. The darkness in the closed, claustrophobic room was oppressive and bright around the edges from the white-hot coals and the yellow flames. All the shadows jerked and twitched. They were sharp and terrible, and they looked violent against the walls and the machinery.

“Stay away from me!” Briar shrieked, only barely thinking that they might not understand her, or even be able to hear her very well through the mask. She brandished the rifle, swinging it and jabbing it at the air.

They held up their hands and retreated, still talking rapidly in spits and bursts. Whether or not they spoke English, they spoke gun.

“How do I get out of here?” she demanded, on the off chance that someone understood her language better than he could communicate in it. “Out! How do I get out?”

From the corner, someone barked a single-syllable reply, but she couldn’t hear it clearly. She quickly turned her head to glimpse the source and saw an elderly fellow with long white hair and a beard that came to a scraggly, pale point. A white film covered his eyes. Briar could see, even in the orange-and-black fever of the bellows room, that he was blind.

He raised a thin arm and pointed to a corridor between a furnace and a machine the size of a cart. She hadn’t seen it before. It was only a black sliver as wide as a drawer, and it seemed to be the only means of entry or exit.

“I’m sorry,” she said to him. “I’m sorry,” she said to the rest of them, but she didn’t lower the rifle. “I’m sorry,” she said again as she turned herself sideways and dashed for the hallway.

Into the narrow space she ran. After a few feet something slapped against her face, but she burst past it and kept jogging madly, into a better-lit walkway pocked with candles shoved into crannies. She glanced over her shoulder and saw long strips of rubber-treated cloth hanging down like curtains, keeping the worst of the smoke and sparks out of the brighter thoroughfare.

Here and there she saw slotted windows to her left, covered and stuffed with more treated cloth, papers, pitch, and anything else that might insulate and seal out the awful gas outside.

Briar was panting inside the mask, fighting for each lungful of air. But she couldn’t stop, not when there might be men chasing her, not while she didn’t know where she was.

It did look familiar, she thought. Not very familiar—not an oft-visited place, but a location she might’ve seen once or twice under better circumstances, and brighter skies. Her chest hurt, and her elbows ached a little from the bruising descent through the waving yellow tube.

All she could think was out: where the exit might be, where it might lead her, and what she might find there.

The hallway opened into a large room that was vacant except for barrels, crates, and shelves stocked with all manner of oddities. There were two lanterns, too, one at each end of a long wooden counter. She could see more clearly in there, except for the cutoff edges of her peripheral vision.