The abandoned shrine near the east canal looked too small to be worth guarding.
That was probably why it had lasted this long without anyone paying it any attention. Orario was full of old buildings like it: cracked walls, the worn marks of forgotten gods, stories nobody could be bothered to check anymore.
This one sat wedged between two warehouses and a narrow drainage path, half swallowed by moss and bad weather, its roof sagging low enough that Gareth had to duck before he even reached the door.
The canal ran past it, carrying dark water through the district, slow and foul-smelling under the early morning mist.
A handful of Guild workers had blocked off the nearest street with the excuse that they were repairing old drainage stones.
Ganesha Familia worked the perimeter in plain gear, so they passed for local security rather than an operation team.
Two alleys away, Eina held the temporary command post with the maps, the reports, and enough worry to fill the whole building on her own.
Rayleigh stood in front of the shrine with the remote tester case in one hand and the new life-check charms tied under his glove.
Welf hadn't come this time.
He had wanted to.
That much was obvious from the way he'd handed over the updated gear with his jaw tight and his eyes fixed anywhere but Rayleigh's face.
Hephaestus had killed the argument before it could start, and for once Welf had swallowed his pride fast enough to keep the moment from turning ugly.
His work was going into the tunnel. For a first operation, that was already more than enough.
The new tester felt heavier than the first. Welf had reinforced the casing, cut the inner channels deeper, and added a locking plate so the route couldn't drain the thread as easily.
It was still ugly, but Rayleigh had learned to respect ugly tools that did their job.
Finn gave the shrine a quiet look, then turned to the group. "Same rules as before. Keep the talk short inside, no names, and nobody follows a sound without confirmation. If the passage opens, we test before we enter. If the route tries to split us, we leave."
Alise adjusted the charm under her glove.
She looked calmer than yesterday, though Rayleigh knew better than to mistake calm for comfortable. "If someone living is inside, we bring them out."
"If someone living is inside and reachable," Finn said. "That last part matters."
"It does." This time she sounded like she'd spent the whole night forcing herself to accept the ugly half of the rule.
"I know."
Kaguya wiped the edge of her blade with a cloth and slid it back into place. "I'm starting to dislike how clever this tunnel is. Traps are easier to laugh at when they don't learn."
Ryuu stood by the canal wall, watching the water instead of the shrine. "There's airflow under the stones. It's weak, but it keeps changing direction."
Riveria moved closer and lowered her staff toward the shrine floor. "The magic here is thin. That may be deliberate. A passage hidden under a canal would be hard to detect if the water keeps washing the traces away."
Gareth looked the old building over. "Then let's not trust the floor."
"That's becoming a theme too," Rayleigh said.
Finn gestured toward the entrance, and they went in.
The shrine smelled of dust and old wood, damp stone and stale offerings.
Someone had cleaned it once, years ago maybe, then given up when no one came back to pray.
The little altar at the back still held a cracked bowl and a stone figure whose face had been worn smooth by time.
Moss had crept in through one corner of the floor, and thin, ugly water marks ran along the base of the wall.
Rayleigh crouched by the altar and brushed his fingers just above the stone without touching it.
There was a hollow beneath them.
Small, at first. More like a pocket of trapped air under the shrine, with several narrow channels branching off it.
The canal muddied the reading.
Moving water washed away scent and smeared the old traces together until everything went soft at the edges.
It was exactly the kind of place a hidden door would like.
He set one of the new markers into the floor beside the altar and filled it, slow and careful.
The signal sank deeper than before and held.
"Good," he said. "The new design likes stone better than the old one did."
Kaguya glanced at the marker. "Should we send the brat a thank-you letter if we live?"
"He'd pretend not to care and read it three times," Rayleigh said.
Alise gave him a small look. "That sounds very specific."
"It's very accurate."
Finn didn't rush them.
He let the exchange run its course, then pointed at the altar. "Tester."
Rayleigh linked his thread to the inner core and stepped back behind the shrine pillar.
Finn pulled the cord.
The tester knocked out the first rhythm. Two taps, a pause, three taps.
For several seconds the altar did nothing.
Then the water answered.
A ripple ran through the canal outside, soft enough that a normal person would have missed it. The moss in the corner darkened.
Water seeped up between the stones and formed a thin ring around the altar before draining back down through cracks that hadn't been there a heartbeat earlier.
Rayleigh felt the tester's first anchor flicker.
The second held.
The third handed him a clear direction through the floor, down and slightly east, following the canal line.
"The door's under us," he said. "The altar's only the trigger."
Riveria kept her voice low. "Is the water part of the mechanism?"
"Looks that way. If someone opened this without a marker, the whole floor might shift before they even worked out where the route started."
Gareth frowned at the wet stones. "That sounds like a fine way to drown in a shrine."
The altar clicked.
A rectangular section of the floor slid aside, not with the heavy scrape of stone but with a smooth, wet sound, as if the edges had been kept slick for years.
A narrow stairway opened beneath it, dropping into darkness alongside an old drainage channel.
Cold air rose from below, carrying the smell of canal water and rust and something faintly sweet that Rayleigh disliked on sight.
Ryuu's ash slid down the first few steps and came back slowly. "No one close. The air moves farther down."
Finn studied the opening. "We go as far as the first junction, no further without a confirmed route. Mark every turn."
Rayleigh picked up the tester and checked the casing. The first anchor was damaged again, but the second and third were alive.
Welf's design had bought them the answer without spending the tool. That was progress.
"Tester's still good for one more knock," he said. "Two, if the wall's feeling generous."
Kaguya looked into the stairwell. "I've yet to meet a generous wall."
"Then one."
They started down.
The stairway was narrow enough that Gareth had to turn sideways in places. Water ran along a channel beside their feet, not deep but steady, and the old stones were carved with small grooves that guided the trickle downward.
Rayleigh kept one hand near the wall without touching it, reading the pressure through the markers he set along the way.
The route here felt different from the breathing wall.
Less hungry. More patient.
He kept that to himself.
"Patient tunnel" wasn't a phrase anyone needed to hear while walking under a canal.
At the bottom of the stairs the passage opened into a low corridor with water running down the center. The air was colder here. Lantern light caught the channel and trembled across the walls, so the whole place seemed to move even while everyone stood still.
Riveria murmured a soft spell, and a thin skin of wind spread around their boots to keep the water off. "Don't step into the channel. If the mechanism uses water to carry signals, contact may matter."
Rayleigh nodded. "Good call."
Alise looked down the corridor. "Left or right?"
The map was no help. By the Guild's records, there shouldn't have been a corridor here at all.
Rayleigh set the tester down and aimed it at the left wall first. Finn gave him a nod.
The first rhythm knocked.
Nothing opened, but the water in the channel slowed, and the charm under Rayleigh's glove tugged faintly to the right.
"Something alive on the right," he said.
Alise's focus snapped to it at once.
Ryuu checked with Haineko. "Breathing. Very faint. Behind the right wall."
Riveria's magic confirmed it a moment later. "A living presence. Weak."
Finn's face stayed calm, but his eyes moved fast across the corridor. "Check for bait first."
Rayleigh set three markers around the right wall and fed power into them.
This time the stone didn't breathe.
It sweated.
Drops gathered along the cracks and slid down into the channel, and the signal inside the markers bent toward the living presence without snapping.
"Stable enough to open," Rayleigh said. "No promises after that."
Gareth shifted his shield. "That's the best kind of bad news."