Yuan found a corner behind the supply cache where the light didn't reach.
He sat down, properly, for the first time since the anomaly, and let the accumulated weight of the last two hours settle into his legs and his back and the specific exhaustion behind his eyes that came from sustained high-alert focus. His left arm had stiffened almost completely now, the wound closed by some combination of Vitality increase and Stony Skin's passive reinforcement, but the muscle around it had decided it was finished cooperating for the foreseeable future.
He didn't open his status window. He'd memorized what was in it.
Instead he sat and listened to the hall calibrate itself around him, the soft noise of sixty people doing the difficult work of coming down from the kind of fear that lives in the body rather than the mind. Someone had started distributing water from the emergency cache. Someone else had organized the walking-capable into carrying stretchers for the ones who weren't. The ordinary logistics of survival, which were somehow more exhausting to witness than the fighting had been.
Forty-seven minutes.
He'd been counting since the quest notification. Forty-three now, approximately, accounting for the time spent watching Li Meilin and moving to this corner. The dungeon's ambient mana was still elevated, his Sense was reporting it as a steady background pressure rather than the sharp spikes of active monster presence, which meant the immediate corridors were clear but the dungeon itself was still running at C-rank saturation throughout.
And somewhere below them, apparently, something was making it worse.
He looked at the quest notification again, which he hadn't closed.
[Hidden Quest: Source of the Anomaly]
[Objective: Locate and neutralize the spatial distortion node at the dungeon's lowest level.]
[Warning: Additional anomaly expansion in progress. Estimated time to next threat level upgrade: 43 minutes.]
Neutralize; the system used that word without explaining what it meant practically. Neutralize could mean destroy. It could mean interact with. It could mean kill whatever was generating the distortion, which raised the question of what kind of thing generated spatial distortion nodes inside academy training dungeons and what rank it would be when he found it.
He had B-rank passives and a C-rank movement skill and base stats that were still functionally F-rank underneath the incremental bumps.
Non-transferable, the quest had said. Assigned to host only.
Which presumably meant Li Meilin couldn't do it. Couldn't receive the quest, couldn't complete the objective, couldn't prevent the next threat level upgrade even if he told her everything and she believed him and they went together. The system had given this specifically to him, and the system's criteria for that decision presumably had something to do with the SSS-rank talent that was the only reason he was alive to be assigned anything.
He exhaled slowly.
Forty-two minutes.
---
Li Meilin was asking Jiang Rui quiet questions near the center of the hall.
Yuan tracked it peripherally, not wanting to watch too directly. Their body language was contained, the kind of conversation two people have when they don't want to worry the people around them, heads angled slightly inward, voices low. Jiang Rui was gesturing toward the spot where the Gargoyle King had been, then toward the entrance corridor, then toward the column where Yuan had spent most of the fight.
Li Meilin listened without expression.
Then she asked something that made Jiang Rui pause and look at the same column again more carefully.
Yuan looked away.
He caught two other conversations fragmentarily as he moved through the hall, a pair of first-years who'd been near the right wall during the Stone Burst, comparing notes on what they'd seen or thought they'd seen. Neither account was specific enough to be useful to anyone. One of them mentioned a shadow that moved wrong and the other mentioned something hitting the boss from behind and they eventually arrived at the shared conclusion that the dungeon's spatial distortion had probably produced visual artifacts.
That was a comfortable explanation. He hoped it held.
He was near the entrance corridor when Li Meilin appeared at his peripheral left.
She was moving parallel, heading toward the same corridor to check the watch rotation. But she was close enough that pretending not to notice would be conspicuous, so he turned and met her eyes and produced the most neutral expression he could manage.
She looked at him for a moment. F-rank badge, support build, the kind of student her spatial awareness probably registered as background rather than variable.
"You're Yuan Shenzi," she said. It was not a question.
"Yes."
"From the graduation cohort." Still not a question.
"Yes."
A pause. She was doing the same thing she'd done from across the hall, filing, assessing, running the information through whatever processing she used for things she couldn't fully account for. He watched her eyes and kept his face still.
"You were at the back during the boss fight," she said.
"I stayed out of the way," Yuan said. "Not much an F-rank Mana Sense can contribute to a C+ boss encounter."
She held the eye contact for one second longer than comfortable. Then she nodded, once, and moved past him toward the watch rotation.
He let out a breath he'd been holding since she'd said his name.
---
The path down had opened while they were fighting the Gargoyle King.
Yuan found it on the south side of the hall, a section of wall that hadn't been there before the anomaly, or rather a section of wall with a door-shaped stress fracture running through it that the Stone Burst's pressure wave had apparently finished for them. Through it: stairs, descending, cut from the same stone as the rest of the dungeon but darker, the mana-reactive moss absent on these walls. The air coming up from below had the quality of somewhere the ventilation system hadn't reached.
He activated Shadow Step as a precaution and went down.
The first thing he noticed was the temperature. Not dramatically colder, just different, the ambient warmth of the upper dungeon absent, replaced by something closer to the base-state temperature of unworked stone that had never seen surface air. The second thing he noticed was his Tremor Sense, which had been running quietly since the extraction as a background input he hadn't fully understood yet, suddenly producing something useful: vibrations, deep and slow, periodic. Not footsteps. Structural. Like a heartbeat, if hearts were made of pressurized spatial distortion.
Below him. Two levels, maybe three.
He descended carefully.
The new corridor system was wrong in ways the upper dungeon hadn't been, angles that didn't quite resolve into architecture, intersections where the spatial geometry implied more directions than were physically present. His Mana Sense reported elevated saturation throughout, and twice he felt the particular spike that meant active monster presence nearby and used Shadow Step to move past before contact.
The first new type he observed from distance: a C-rank construct, roughly humanoid, body composed of compressed wind mana cycling through a stone frame. It moved with a rigid, deliberate quality, patrol pattern consistent, and when it passed a wall sconce the wind mana in its chest cavity made the flame lean toward it rather than away.
He noted it and kept moving.
The second: something lower, quadrupedal, moving in the shadows on the far side of a wide chamber. Mana signature cold and structured, similar to Li Meilin's ice affinity but rawer, elemental rather than trained. It hadn't detected him. He went around the chamber's perimeter wall.
He was three levels below the main hall and still descending when the Tremor Sense input changed.
A single beat, strong enough that the stone under his feet registered it physically, a vibration he felt through his soles before his skill processed it. He stopped and pressed his back against the wall and waited.
Nothing followed. Just the one beat, and then the slow periodic rhythm resuming.
He came around the next corner and stopped.
The corridor ended in a chamber he hadn't been able to see from the approach, not because of distance but because the space itself seemed to be resisting direct perception, the eye wanting to slide away from it rather than engage. He pushed against the instinct and looked.
In the center of the chamber, hovering at chest height, was an object roughly the size of a fist.
It wasn't a mana core, he'd seen those now, knew their visual signature. It wasn't a weapon or a tool or anything he had a category for. It was dark, faceted, rotating slowly on an axis that didn't correspond to any of the spatial orientations available in normal geometry. The mana radiating from it was the most concentrated he'd ever encountered, dense enough that his Sense was having difficulty resolving it into anything readable.
The slow periodic pulse was coming from it. One beat every four seconds, and every time it beat the fracture in the spatial geometry of the chamber, which he could now perceive as an actual visible thing, a hairline crack running from the object's position upward through the ceiling and, presumably, through every level above them, widened fractionally and then returned.
Not to its previous width.
To a width that was slightly larger than before.
[Ding!]
[Anomaly Source Detected: Fractured Dungeon Core]
[Status: Unstable. Deterioration rate accelerating.]
[Warning: 38 minutes to critical threshold.]
Yuan looked at the object.
The object rotated slowly and pulsed, and the crack widened and didn't fully close, and somewhere three levels above him sixty students were treating their injuries and drinking emergency ration water and not knowing that the thing responsible for their situation was the size of a fist and apparently his problem specifically.
He thought about neutralize.
He thought about what his right hand did when it was close to something with a core.
Oh, he thought.