Once, years before the Cyran Empire first opened the gate and stormed through the Cauldron, Eolh was on the run. He had been caught stealing fruits—and maybe a couple of bottles of finest fruit wine—from a Midcity merchant. A falkyr guard was on his tail.

He flapped and flitted and scrambled through the grimy streets of Lowtown, weaving through ragged canopies and tangles of hanging clothes, ducking under crooked balconies and lamplit windows.

The door to a basement, where an old herbalist made her potions and pastes, caught his eye. He ducked inside and slammed the door behind him.

It took only a moment before the smell of death made him gag and cough.

Something had killed the herbalist. He never found out what. But her body was covered in hundreds of small, white mushrooms that pushed out of her gray and white feathers. He could taste the bile rising in his throat.

Eolh hid in that room for only a few minutes, but the smell never left his memory.

Now, years later and miles below the Cauldron, Eolh felt as though he were walking right back into that death-choked basement.

Down here in the muddy tunnel, the concrete walls and the ceiling and the floors were covered in fungal growths more numerous than the stars. Black tubers with fleshy bodies, white caps and morels with spongy skin, and massive shelves of fungal rings that glistened wetly as they passed, backlit in blue from the old emergency lights.

The smell was a mixture of stale water, old growth, and fresh rot. Life that feeds on death. It burned his throat and made his eyes water, and it was all he could do to keep himself from vomiting.

If they ever made it back to the surface, he would have to burn his clothes. No way is this stench coming out.

The human, on the other hand, seemed less affected. Perhaps his sense of smell is worse than mine?

The human had been silent for the last hour or so. Even Poire’s footsteps had slowed, though Eolh suspected it was less from exhaustion and more from despair.

This cramped tunnel—with barely enough room for them to walk single file—was covered in filth and grime and death-eating fungus. And this was supposed to be the way to his home.

He almost felt bad for the fledgling human. Sure, some corvani had sprawling, vivacious families, but Eolh—except for his time with the old crew—had always been alone.

In a way, Lowtown was kind to loners. Nobody cared about what you did. Not really. Which meant he didn’t have to care about anyone else. It was so much easier that way. You lived; you did what you could get away with. And then you died.

That was Lowtown. That was life. Not even the imperials could take that away.

But the human?

If he had a family, they were gone. If he had friends . . . well.

Lowtown was full of loners.

But none so alone as Poire. He was the last one.

There were no other humans left, and there never would be again.

Eolh opened and closed his beak a couple times, tasting the air. It made him gag, but now he was certain.

“It’s getting stronger,” he choked out. “We must be close.”

Poire was crouched in the slow-moving trickle of water. His feet, covered in that strange, formfitting fabric, sank into the black mud. He was pulling clumps of fungus off the curving wall of the tunnel, slowly revealing a drawing etched into the cracked concrete. Meaningless symbols and simple shapes dancing around a rough face with closed eyes.

“What is this?” Poire asked, but instead of curiosity, his voice held only a quiet, shaking fury. Like something had been stolen from him. Maybe he’s starting to accept the truth.

“Who did this?” Poire asked again, pointing an accusing finger at the wall.

Eolh held Laykis’s eye out to inspect it. “Sajaahin, maybe? Judging by the height and the, ah, crudity?”

“This is wrong.”

“Look, nobody said they were great artists.”

“No! Not that. I mean, all of this. The tunnel should be clean. Empty. The trains need to run through it. We should hear birds and the fountains and the trees.”

Trees? Eolh thought. Underground?

“If we’re close,” Poire continued, “there should be sunlight!”

“Sunlight?” Eolh asked. “How could there be sunlight?”

“There was always sunlight! Except when we made it rain. You knew you were home when the tunnels started to glow bright as day, but this—” He gestured wildly at the walls and the floors covered in crude drawings and forests of fungi. “This is all wrong, Eolh.”

A sound. Eolh held out a hand to silence the human, but Poire didn’t notice.

“Where are the constructs? The trains? Why is nobody fixing this? Where is—”

“Shut up!” Eolh hissed. “Do you hear that?”

“Hear what?”

Black water trickled through the tunnel, a weak stream going gods knew where. And beyond, a sound like some great, beating heart.

Tha-dum . . . tha-dum . . .

The walls glowed in Poire’s presence, illuminating their cramped pocket of the tunnel.

“Human,” Eolh said. “Can you darken your light?”

“It’s not mine,” Poire said. “It’s the emergency system.”

“What does that mean?”

Poire sighed as if his meaning should’ve been obvious. “They’re bioautomatic. But even if I had admin access, which I don’t, my implant isn’t working. I can’t talk to the city.”

Talk . . . to the city? How does one—

Eolh shook his head, clearing away the thought. “Never mind. We’ll do this the hard way. Stay behind me.”

The water carved a muddy channel through the filth and grime. Eolh’s talons were coated with a slick slime so that he had to stretch out his wings and hold himself steady on the tunnel’s narrow walls. Behind him, the human squelched with every step.

Echoing booms thumped in the distance: the great heart of something, shaking the tunnel and rippling in the slow-moving stream.

And then the tunnel dropped away. The stream trickled over the edge and misted away into a breeze.

A breeze? Down here?

Before he could guess, Eolh saw.

Their tunnel ended at the top of some ancient avalanche. Stone and earth had collapsed a long time ago, and the rubble that had spilled out into the cavernous darkness had softened into a slippery, treacherous decline.

Wind whipped at Eolh’s feathers, and with it came the foul, swampy smell of the ruins below, nestled in the basin of some vast, dark cavern.

Only, could he call this a cavern? He could only see the distant walls because they were lit up in a sea of twinkling lights. Torchlights, maybe. Or campfires. Or stars, for all he could tell.

Eolh gripped the edge of the tunnel with his talons, holding himself steady in the dizzying scale of this place. A wind threatened to push him back or pull him forward.

The cavern floor was dominated by a lone stone hill like some huge stalagmite reaching up toward the ceiling hundreds of yards above. On its peak, three spiraling towers—made of that unmistakable human metal—sat dark and empty, watching over all.

Thousands of crude huts and hovels and mud burrows and broken chunks of masonry radiated around this lone hill, and more holes had been cut into the cavern walls, connected only by rough switchbacks and rotting rope bridges.

Forests of towering fungi glowed in all the expanse below, some almost as tall as kapok trees. They grew on the walls, on the roofs of the hovels, and in the muddy black rivers. They grew everywhere but the metal tracks that crisscrossed the floor of the cavern making patterns shaped like the petals of a flower.

“My city,” the human said. “My home. It’s . . . it’s . . .”

“It’s incredible.”

“It’s gone.”

The fledgling human made a sound in his throat. Eolh thought he was about to faint. Instead, he sank into the mud with a treacherous moan. “How? How?”

Time comes for us all, Eolh thought. Even the immortal gods, it seems.

Eolh knew not how long they stayed there staring out into that incredible space, at all those twinkling lights, listening to the sound of some great, beating heart. He knew not if he was supposed to do something.

What am I supposed to say? he thought bitterly. Should I give comfort when none was ever given to me?

A dim whiteness, fainter than the faintest mist, was growing from the farthest edge of the cavern, where the floor met the wall. All the firelights in all the hovels seemed to fade, but it was only the growing of that one light swallowing all the rest.

As the whiteness grew, so did the beating of that great heart.

Tha-dum . . . tha-dum . . .

Drums.

Yes. He was sure of it now. The Sahaat was drawing near.

A slow, pale dawn began to break into the cavern, filling this impossible space with light.

In the distance, Eolh caught movement. Some nameless creature—by the gods, what is that thing?—broke away from the huts and began to crawl with long, spindly limbs up the wall, slipping into some black crack as it fled from the sound of the drums.

What the hells else could be down here?

“I didn’t ask for this,” Poire said. “This isn’t what I wanted.”

But now, his voice didn’t shake, nor were there any tears on his face. The human clenched his hands into muddy fists so that his knuckles turned a paler brown.

“I have to find her,” he whispered. And before Eolh could do anything, the human pushed himself to his feet and started to climb down.

“Human!” Eolh hissed. “Wait!”

The human slipped in the mud, his feet skidding over rock and stone and wet dirt. But he did not stop.

“Gods damnit,” Eolh clicked his beak in frustration and flapped after him. All the while, the foul breeze blew and the light from the Sahaat gained in brilliance.

Eolh caught up to him at the base of the avalanche, where the floor leveled out and a cluster of disused huts rose out of the mud. Some of them were shattered and falling back into the mud.

The distant clattering noise of instruments carried over the low-slung huts and the cupped canopy of giant fungus. Bright blue and green and pale white veins glowed through the mushrooms, casting strange shadows as they skirted the edge of the forest.

Poire seemed to see none of it.

“Human, wait. We don’t know this place.”

“I do,” he said. “I used to run all over this place. Up there—that’s my home. That’s where we live. I eat breakfast there, every morning, so I can look out over the Conclave. And there are trees growing under the minarets.” He pointed to the stone hill in the center of the cavern, where nothing but black fungus grew. “Glass trees. Silver leaves and crystal bark that you can see right through. And the false suns overhead. This is where it fell whuh . . . when . . . What happened to my home?”

There are moments in one’s life where one wishes one hadn’t said anything at all. As soon as he opened his beak, Eolh knew this was one of those moments.

“It could be worse,” Eolh said.

“How?” The human stopped so abruptly Eolh almost lost his footing. “How could this be any worse?”

“Easy,” Eolh warned. “Take it easy.”

“Why?” the human shouted even louder. “Why does it matter what I do? Why does anything matter now? You were right—everything is gone. Everyone.”

“What about you?”

“I never wanted to be here!” The human’s eyes were wide and filled with white. He was grabbing at his chest, pulling the strange fabric of his suit away from his skin. Sweating and gasping for breath. “I never wanted any of this!”

And all the while, the drums grew louder, and the dawn filled the cavern with light.

Panic. He had seen it too many times. On the job, panic always got someone killed. Or worse. He had to bring the human back down. Shouldn’t have let him get this far in the first place.

“Calm down,” Eolh hissed through his beak. “You’re losing your grip.”

“It’s gone. My home. My conclave. Xiaoyun. I saw her. I saw her, and she was nothing but bone, and there was hair sticking out of her skull, and—”

Eolh reached out to grab Poire’s shoulder, meaning to ground him, to hold him steady. But the human was fast. Faster than Eolh expected.

He jerked away from Eolh, stepped back toward the forest of mushrooms. “Don’t touch me!”

“I’m here to help you, human.”

“Why?” Poire shouted.

It was such a simple question. He could’ve said anything, anything at all. But nothing came up.

“I don’t know you. I don’t even know what you are! I have to find someone. I have to see if anyone is left—”

“Listen!” Eolh cut him off. “The android said—”

CRACK!

A gunshot ripped through the air, deafening the din of Sajaahin instruments rising somewhere from the other side of the cavern. Far across the ruins of the human’s city, something heavy dislodged and crashed to the ground.

CRACK-tawoon! Another shot ricocheted on the dried-mud hut to his left. The hut exploded in crumbling shards of caked dirt.

Eolh ducked. “Get down!” he shouted, and the human actually listened.

Together, they huddled against the remains of the hut, keeping their heads low.

When he peeked out, another bullet screamed in front of his face and the wind streaked over his beak. He jolted back to cover.

“What is that?” Poire whispered hoarsely. “What is that?”

It was new tech. A long-range endloader rifle, probably, if they were shooting from that distance. Cyran-made. Eolh peeked out one more time. Another shot.

No, he corrected himself. Two endloaders. At least two.

“Are those guns?” Poire asked. “Are they shooting at us?”

“No, they’re shooting at me,” Eolh said.

“Why?”

“Because of you.”

That shut him up, which let Eolh focus on the problem at hand. How did they find us? And how many are there? He sank back against the mud hovel, trying to find an escape.

“OK,” he said breathlessly. “I’ll go that way. You run into the forest. I’ll catch up with you after I’ve drawn them away. Ready?”

Before he could answer, the hut exploded.

Gunshots whistled through shards of dirt and dried mud and dust, splattering Eolh and Poire both. In all that dust, Poire just stood there with his mouth open.

“Run.” Eolh shoved the human toward the forest. “Run!”

The human plunged into the fungal undergrowth, crashing and knocking the flesh caps off the smallest mushrooms.

Eolh flexed his legs and threw himself in a different direction, hoping to draw their fire away from the fledgling human. He turned and juked and swiveled with each thrust of his wings, hoping to avoid the gunshots. Two more sang past him. One clipped a feather but missed his arm. Eolh dove down into the undergrowth.

A light split open the dark. It came from across the cavern, casting mad shadows over everything on the cavern floor. And then, a roar that shook the ceiling.

Shouts and screaming ululations and the sound of bleating horns crashed through the cavern. Echoing and echoing until it felt like they might bring down the ceiling through sound alone.

The fungal trees shook with the noise, their skirts unfurling and dumping clouds of spores from their canopies. Through the dust, Eolh could see the source of all that light.

An old human train, floating above the rails, surrounded by a sea of torches and hobbled, ragged people.

The Grand Sahaat had arrived, and the human was headed straight toward it.