The lower markets looked different in the morning.
Shen Yuan had only seen them in the afternoon before, when the cavern was crowded with disciples and merchants and the kind of desperate energy that came from people trying to survive. Now, with the green flames still burning but the natural light from above barely a suggestion, the place felt almost peaceful. The merchants were setting up their stalls, yawning and stretching and arguing about prices in low voices. The disciples hadn't arrived yet. The cavern belonged to the sellers.
"The turnip seller," Lian Jie said, scanning the stalls. "Cai Ling said he had no teeth."
"There." Wei Cheng pointed.
The stall was in the corner of the cavern, tucked between a butcher selling something that might have been meat and a woman offering love potions in cracked clay bottles. A wooden sign hung above it, painted with a single turnip that had been crudely carved and even more crudely colored. The man behind the stall was old—older than anyone Shen Yuan had seen in the fortress, with skin like dried leather and eyes that had gone milky at the edges. His mouth was a dark hole in his face, empty of teeth, and when he saw them approaching, he smiled.
It was not a reassuring expression.
"Customers," the old man said. His voice whistled through the gap where his teeth should have been. "Early customers. You must want something special."
"Pickled radishes," Shen Yuan said.
The old man's milky eyes moved across his face. Lingered on his robes, on the cleaver hidden beneath, on the way Lian Jie stood with her hand on her sword.
"Pickled radishes," he repeated. "Haven't had a request for those in years. Don't usually carry them. But for you—" He reached under his stall and pulled out a small clay pot, sealed with wax. "I might have a few left. Special batch. Very special."
He set the pot on the counter. Then he leaned forward, close enough that Shen Yuan could smell the rot on his breath.
"The woman you're looking for lives in the Warrens. Below the markets. There's a grate behind my stall—lift it, climb down, follow the smell of cooking oil. When you find her, tell her the turnip seller sent you. She'll know what it means."
"She'll also know you sent strangers to her door," Lian Jie said. "That seems risky."
The old man shrugged. "I'm old. I'm toothless. I've been selling turnips in this cavern for forty years. No one cares about me. No one watches me. That's the advantage of being nothing."
Wei Cheng flinched at the word. Shen Yuan noticed.
"Thank you," he said, and picked up the clay pot. It was heavier than it looked, and warm, as if something inside was still alive.
"Don't thank me," the old man said. "Just don't get her killed. She's my niece."
---
The grate was exactly where he said it would be.
Behind the stall, half-hidden by a stack of rotting crates, an iron grate sat flush with the stone floor. The bars were rusted, thin in places, and when Shen Yuan pulled, the whole thing came up with a screech of protesting metal.
Below, darkness. And below the darkness, the smell of cooking oil.
"I'll go first," Wei Cheng said.
"Why?"
"Because I've been in the Warrens before. It's not a place for people who don't know the paths."
He dropped through the opening before Shen Yuan could argue, landing with a soft thud on whatever lay below. Lian Jie went next, her sword drawn, her face set in the expression she wore when she was expecting a fight.
Shen Yuan went last. The drop was shorter than he expected—maybe eight feet—and he landed on packed dirt instead of stone. The ceiling above him was low, barely higher than his head, and the walls were made of the same rough rock as the rest of the mountain. But the floor was different. Soft. Almost warm.
The Warrens.
They walked for what felt like miles, following the smell of cooking oil through a maze of tunnels that branched and twisted and doubled back on themselves. The green torches were gone here—instead, small clay lamps sat in niches in the walls, burning with ordinary orange flame. The light was almost comforting after the sick glow of the fortress above.
People lived in the Warrens. Shen Yuan could see them in doorways, in the shadows, watching as he passed. Families huddled together on thin mats. Children with hollow eyes and empty bowls. Old women stirring pots of something that smelled like nothing he had ever eaten. The Warrens were where the fortress hid its poor, its forgotten, its nobodies.
Wei Cheng walked like he belonged here. Like he had walked these tunnels a thousand times before. Maybe he had.
"The cooking oil is getting stronger," Lian Jie said.
"We're close."
They turned a corner and found her.
The woman was younger than Shen Yuan had expected—maybe thirty, maybe less. Her face was round and plain, the kind of face that existed to be overlooked. She stood over a clay stove, stirring a pot of something that bubbled and spat, and when she looked up at them, her eyes were the color of the dirt beneath her feet.
"You're not from the Warrens," she said. Her voice was flat, unimpressed. "You walk like people who live in the light. Your boots don't have holes. And you—" She pointed at Shen Yuan. "You have the look of someone who's never been hungry a day in his life."
"I've been hungry," Shen Yuan said.
"Not like this."
No. Not like this.
"The turnip seller sent us," he said. "We need to talk about Elder Xu."
The woman's face went very still. Her hand stopped stirring. The pot bubbled on, ignored.
"I don't know anyone named Elder Xu."
"You know his kitchens. You've worked in them for ten years."
"I'm a cook. I cook. I don't know anything about politics or vaults or—"
"Cai Ling said you would help us."
The name landed like a stone dropped into still water. The woman's eyes widened, just for a moment, before she controlled herself.
"Cai Ling," she repeated. "The woman whose brother died."
"Yes."
"She said I would help you?"
"She said you wanted protection. A way out. She said you'd seen things in Elder Xu's compound—things that could prove he was behind the demon summoning."
The woman was quiet for a long time. The pot bubbled. Somewhere in the tunnels, a child cried. When she spoke again, her voice was so soft Shen Yuan had to lean forward to hear.
"There's a vault beneath the kitchens. Elder Xu's personal storehouse. He thinks no one knows about it, but I've been there. I've cleaned the floors. I've seen the ledgers he keeps, the records of every transaction he's ever made. They're all there. Every bribe. Every murder. Every demon he's summoned and controlled."
She set down her stirring spoon and wiped her hands on her apron.
"If I show you how to get in, you have to promise me something."
"Name it."
"When this is over—when Elder Xu is dead or exiled or whatever happens to people like him—you get me out of here. You take me somewhere far from this mountain. Somewhere with sun. Real sun, not the green kind. Somewhere I can cook for people who don't want to kill me."
Shen Yuan looked at her. At her dirt-colored eyes, her flour-dusted apron, her hands cracked and callused from ten years of stirring pots in a demonic sect's kitchen.
"You have my word," he said.
The woman studied him for a moment. Then she nodded.
"There's a passage behind the third stove in the main kitchen. It leads to a service tunnel that runs under the compound. Follow it to the end, and you'll find a door—iron, locked, with a formation array that will kill anyone who touches it without the key."
"The key?"
"I have it." She reached into her apron pocket and pulled out a small iron key on a leather cord. "I've had it for eight years. Waited for the right moment to use it. I think this is the moment."
She held it out. Shen Yuan took it. The key was warm from her body heat, and heavier than it looked.
"The formation array," she said. "You can't break it. You can't bypass it. But you can fool it. There's a blood seal—Elder Xu's blood, keyed to his spiritual signature. If you can replicate that signature, even for a moment, the array will open."
"How do I replicate someone's spiritual signature?"
The woman looked at Wei Cheng. Then at Lian Jie. Then back at Shen Yuan.
"You don't. But there's a woman in the Warrens who can. She's old. Older than the turnip seller. She lives at the end of the lowest tunnel, in a room made of bones. If anyone can help you, she can."
"A room made of bones," Lian Jie said. "That's not ominous at all."
The woman almost smiled. "Welcome to the Warrens."
---
They found the bone room an hour later.
The lowest tunnel was exactly that—the lowest. Shen Yuan had to duck to walk through it, and even then, his head brushed the ceiling. The clay lamps were fewer here, further apart, and the darkness between them felt thick enough to touch. The smell of cooking oil had faded, replaced by something older. Something that had been in the mountain long before the fortress was built.
The door at the end of the tunnel was made of femurs.
Not carved to look like femurs. Actual femurs, human-sized, bound together with wire and something that might have been sinew. The handle was a pelvis. The hinges were ribs.
"This is not normal," Wei Cheng whispered.
"We're in a demonic sect," Lian Jie said. "Nothing is normal."
Shen Yuan knocked on the bone door. The sound was wrong—too hollow, too loud, echoing in the tunnel like a drumbeat.
"Enter."
The voice came from inside. Old. Female. Tired in a way that had nothing to do with sleep.
Shen Yuan pushed the door open.
The room beyond was small, barely larger than his own chamber in the fortress above. But where his room was stone and shadow, this room was bone and candlelight. Skulls lined the walls, arranged in neat rows. Rib cages hung from the ceiling, clinking together softly in a draft he couldn't feel. And in the center of it all, sitting on a throne made of spines, was a woman so old she looked like she had been carved from the mountain itself.
Her skin was gray. Her hair was white and thin, pulled back from a face that had collapsed inward over the years until only her eyes remained prominent. Those eyes were black—not dark brown, not the color of old coins like Lian Jie's, but actual black, the black of a sky with no stars.
"You're the Heavenly Demon's son," the old woman said. "I can smell him on you."
"You can smell my father?"
"I can smell the blood that made you. Old blood. Angry blood. Blood that has been waiting for something for a very long time." She tilted her head. "You don't know what you are, do you?"
"I know I'm Shen Yuan."
"That's your name. Not what you are." She reached out with a hand that was more bone than flesh. "Give me the key."
Shen Yuan hesitated. Then he pulled the iron key from his sleeve and placed it in her palm.
The old woman closed her fingers around it. Closed her eyes. When she opened them again, they were no longer black.
They were red.
"The blood seal on this key is strong," she said. "Elder Xu has been feeding it for years. Keeping it alive. Keeping it hungry." She looked at Shen Yuan. "To fool it, you will need to feed it something it wants more than Elder Xu's blood."
"What's that?"
"Yours."
Lian Jie stepped forward, her hand on her sword. "Absolutely not."
"Your opinion has been noted and dismissed," the old woman said without looking at her. "The boy's blood is special. He doesn't know it yet, but the seal will recognize it. It will prefer it. And for one moment—one heartbeat—it will open."
"How do you know my blood is special?"
The old woman smiled. It was the worst thing Shen Yuan had seen since waking up on that stone slab.
"Because I'm the one who put you at the fortress gates," she said. "Twenty-something years ago. Wrapped in black silk. Crying for a mother who was already dead."
Shen Yuan's world stopped.
"You," he said. "You left me there."
"I left you there because it was the only way to keep you alive. Your mother—she was not from this mountain. Not from this sect. Not from this world, really. She came from somewhere else. Somewhere the demons fear to tread. And she died giving birth to you, because the power in your blood was too much for her body to contain."
The old woman held out the key.
"Your father doesn't know this. He thinks you're his. He thinks the blood that runs through your veins is the same blood that runs through his. It's not. You are something older. Something that shouldn't exist in this world. And if Elder Xu ever finds out what you really are—"
"He'll do more than kill me."
"Yes."
Shen Yuan took the key. The metal was warm now, almost hot, pulsing gently against his palm like a second heartbeat.
"How do I fool the seal?"
"Cut your palm. Let your blood coat the key. When you insert it into the lock, the seal will taste what you are. It will open. But only for a moment. You'll have perhaps ten heartbeats to get through the door before it closes again."
"And if I'm not fast enough?"
The old woman's red eyes flickered.
"Then you'll be sealed inside the vault. With Elder Xu's treasures. And his traps. And the things he keeps locked away that even he is afraid of."
Shen Yuan looked at the key. At the bone door. At the woman who had left him at the fortress gates and never looked back.
"Thank you," he said.
"Don't thank me. Survive. That's all the thanks I need."
She closed her eyes. The red faded, replaced by black. When she spoke again, her voice was distant, already moving away from them.
"Go. You have work to do. And not much time."
The bone door swung open on its own. Shen Yuan walked through it, the key hot in his hand, the old woman's words burning in his chest.
He was not what he thought he was.
He was something else.
Something older.
Something the demons feared.
And in three days, when he stood before Elder Xu's vault, he would find out exactly what that meant.