Frostgate's outer wall had been breached in three places.
The damage was visible from the highland road, where sections of stone lay scattered across the slope below the settlement. Repair crews worked beneath the protection of armed guards, hauling blocks into position while merchants waited beside carts loaded with ore. Unlike Northwatch, Frostgate had not closed its gates completely, but every traveler entering the town was inspected, and no one was permitted to approach the eastern mining district.
Subin's team reached the gate shortly before noon.
A guard checked their identification, then looked at the weapons carried by the expedition. "Are you here to trade or to register with the local Association office?"
"Neither," Subin replied. "We're passing through. Northwatch mentioned that your mining district had been closed."
The guard's expression tightened. "Then you should speak to Commander Rhea. She's been looking for people capable of handling the problem."
They were escorted through the gate to a fortified administrative building overlooking the damaged wall. Commander Rhea was waiting with several officers and a stack of reports spread across a table. She was a tall woman with short hair, a scar across her cheek, and the posture of someone who had spent too many nights awake.
"Northwatch sent word that you recovered their missing patrol," she said. "If that's true, I have a job for you."
"Tell us what happened first," Subin replied.
Rhea pointed to a map of the eastern mining district. Frostgate's wealth depended on several quarries and underground iron deposits, but three weeks earlier, workers had discovered a series of deep cracks beneath the eastern wall. The cracks widened over the following days, and the ground began sinking around the oldest mine.
At first, the miners assumed the supports had weakened. Then a section of the mine collapsed, killing two workers and trapping several others. Creatures emerged from the broken tunnels soon afterward, forcing the guards to seal the entire district.
"We've fought off several groups," Rhea explained, "but the attacks continue. The creatures don't come directly for the town. They target the damaged sections of the wall and the abandoned mines."
"How many types have you identified?" Ara asked.
"One kind. Heavy-bodied creatures with stone plates. They're smaller than the ones that attacked Stonehaven, but they travel in groups. We killed four, and two more escaped into the tunnels."
Ara exchanged a glance with Subin. "Did the ground collapse before the creatures appeared, or after?"
"Before. But the collapses became worse once they arrived."
"Then the creatures may be exploiting existing tunnels rather than causing the original damage," Ara said. "We need to examine the mine before deciding."
Rhea nodded and handed them a key to the eastern service gate. She offered six guards as an escort, but Subin asked for only one guide who knew the mine layout. The rest were needed to protect the wall and keep the repair crews safe.
Their guide was a young miner named Kess, whose brother had been among those killed in the first collapse. He carried a lantern, a short pick, and a narrow notebook filled with rough sketches of the old tunnels.
"The mine was expanded over several generations," Kess explained as they approached the service gate. "Some passages are older than the town itself. The newer tunnels are marked, but the old ones were never properly mapped."
"Why were they left open?" Jae-hyun asked.
"Because the older shafts connect to mineral deposits that are difficult to reach from the newer tunnels. The council wanted to reopen them eventually."
"That sounds like an expensive way to get buried," Jae-hyun muttered.
Kess did not laugh.
Beyond the service gate, the mining district was quiet. Abandoned carts stood near the entrances, and warning ropes blocked several narrow paths. The ground had sunk around the oldest shaft, leaving a jagged depression filled with broken timber and stone.
Ara scanned the area. "There are multiple mana signatures below us."
"How many?" Yerin asked.
"At least eight. They seem concentrated near the old shafts."
Subin studied the collapsed entrance. The stone had not simply fallen inward. Several blocks had been pushed outward from beneath, leaving fresh fractures around their edges.
"Something is moving under the foundation," he said.
Kess led them to a newer tunnel that remained structurally sound. They entered cautiously, following the marked route until they reached a reinforced junction. Beyond it, the old workings began. The walls were rougher, the support beams darker with age, and the floor uneven from years of shifting ground.
They found the first creature near an abandoned ore cart.
It was a squat, four-legged beast about the size of a bull, with overlapping stone plates across its back and thick forelimbs built for digging. Its blunt head pushed against a support beam while its claws scraped away the surrounding rock.
Ara's scanner identified it as a Level 229 A-rank: Shalehide Burrower.
The creature noticed them and charged.
Subin moved aside and cut through the joint behind its foreleg. The blow slowed it, but the Burrower twisted sharply, forcing him to withdraw before its stone-covered shoulder struck him. Yerin's spear penetrated the gap Subin had opened, and the creature collapsed against the wall.
The impact shook loose dust from the ceiling.
"Don't damage the supports," Ara warned. "These tunnels are already unstable."
Subin wiped his blade and nodded. "We'll draw them away from the beams."
They continued past the dead creature and found evidence of a larger colony. Freshly dug passages branched from the old workings, and several support beams had been scraped almost to their cores. The Burrowers were not simply wandering through the mine. Their digging had weakened the structures holding up the eastern district.
A distant crash echoed through the tunnel.
Kess froze. "That came from the lower shaft. There were workers down there when the mine was closed."
"How many?" Subin asked.
"Two crews were supposed to be working in the lower section before the collapse. We recovered some bodies, but we never found everyone."
Ara checked her scanner. "I'm detecting a larger mana signature beyond the next junction."
Subin looked toward the lower shaft. "We'll find out whether anyone is still alive. Kess, stay behind us and mark the route."
The tunnel descended into a chamber where several Shalehide Burrowers were tearing apart an old support structure. Their movements had exposed a natural cavern beyond the mine, with pale mineral veins running through the walls. A large opening in the cavern floor led into darkness.
The creatures had been moving stone away from that opening, piling it near the damaged supports.
At the center of the chamber stood a much larger Burrower.
It was nearly eight meters long, with thick plates covering its shoulders and head. Its forelimbs were broad enough to crush a support beam, and a ridge of pale mineral growth ran along its spine. Each time it dug into the ground, the chamber vibrated.
Ara's scanner displayed Level 258 A-rank: Deepcrag Ravager.
The creature raised its head and charged the nearest support column.
Subin understood the danger immediately. If the column failed, the upper tunnels could collapse and seal the only route back to the surface.
He moved to intercept the Ravager, cutting across its front leg before it could strike the column. The blade bit into the joint, forcing the creature to stumble sideways. It slammed into the cavern floor instead, sending a shock through the surrounding rock.
Yerin attacked the wounded joint, but the Ravager's armor held against her first thrust. She changed her angle and drove the spear into the exposed tissue beneath its shoulder.
The creature roared and swung its head toward her.
Subin cut through the narrow seam beneath its jaw, drawing its attention back to him. The Ravager lunged, and he narrowly avoided the impact. Its claws tore through the ground where he had stood, exposing another fracture beneath the chamber.
"Subin!" Ara called. "The floor is breaking apart!"
He saw the problem. The Ravager's digging had hollowed the ground beneath the chamber, leaving a thin layer of stone between them and the lower cavern. Every heavy impact increased the chance of a collapse.
They could not afford a prolonged fight.
Subin watched the Ravager shift its weight before another charge. Its injured foreleg was weaker, but the creature compensated by driving forward with the opposite side. The movement exposed the underside of its neck for only a brief moment.
He waited until the creature committed.
As it lunged, Subin stepped past the leading claw and cut upward through the damaged joint beneath its jaw. Simple Edge penetrated the exposed tissue, and the Ravager's forward momentum carried it past him. Yerin's spear struck the same opening, widening the wound.
The creature collapsed before it could reach the support column.
Subin delivered a final cut to end the fight. The Ravager's body struck the cavern floor, and the remaining Burrowers scattered into the side passages.
For several seconds, the chamber remained still.
Then a voice came from beyond the damaged support structure.
"Help! Is someone there?"
Kess rushed toward the sound, but Subin caught his arm before he could step onto the cracked floor.
"Wait. We need to secure the passage first."
Rafael and Liu Wei helped Ara identify the safest route around the damaged section. Once the others had reinforced the weakest support with spare timber from the abandoned carts, Subin crossed the chamber and reached a narrow recess behind the collapsed wall.
Three miners were trapped inside. One had a broken leg, and another was barely conscious from dehydration. They had survived by sheltering behind a stone partition when the tunnel collapsed.
Rafael treated the injured men while Yerin and Jae-hyun helped clear a path. The evacuation took time, but the chamber remained stable long enough for the team to bring everyone back to the upper tunnel.
Kess recognized one of the rescued miners as his brother's former partner. The man had been part of the missing lower crew and had spent days trapped underground, believing no one would find them.
When the survivors reached the surface, Frostgate's guards carried them to the infirmary. Commander Rhea arrived soon afterward, visibly relieved that anyone had been recovered.
Subin gave her the report. The Deepcrag Ravager was dead, and the surviving Burrowers had retreated into the natural cavern. However, the old workings remained dangerous, and the eastern wall could not be considered secure until the tunnels were inspected and the weakened foundations reinforced.
"Can we reopen the mine?" Rhea asked.
"Not yet," Ara answered. "The creatures have dug through several old passages, and the ground beneath the district is unstable. You need engineers to determine which sections can be reinforced and which must be sealed."
Rhea's expression tightened. "The mine supplies most of our iron. If we close it for too long, the town will struggle to repair the wall."
"Then recover ore only from the inspected sections," Subin said. "A full reopening is not worth another collapse."
Rhea looked toward the eastern district before nodding. She ordered the old shafts sealed, the surviving miners assigned to safer work, and the damaged wall reinforced with material from the town's remaining stores. The decision would slow Frostgate's production, but it would keep the repair crews from working above unstable ground.
That evening, the town held a small gathering for the rescued miners. Kess stood with them near the infirmary, listening as the survivors described their days underground. He thanked Subin's team afterward, though he struggled to find words that seemed sufficient.
Subin accepted his gratitude without making promises about the future of the mine.
Later, Ara reviewed the scanner readings. The Shalehide Burrowers had been excavating around existing mineral veins, while the Deepcrag Ravager had occupied the largest chamber. Their activity had worsened the damage, but the original ground fractures appeared older than the colony.
"The mine was already weakening," Ara concluded. "The creatures exploited it, but they probably didn't cause the first collapse."
"Then Frostgate needs a geological survey as much as a monster-clearing team," Subin said.
"Exactly."
Yerin leaned against the table. "We've spent several days dealing with creatures that use underground spaces. Do you think the whole northern region is connected?"
"Some passages are connected, but that doesn't mean every creature shares a territory or follows the same pattern," Ara replied. "We should avoid drawing conclusions from a handful of mines."
Subin agreed. The recent encounters had shown that underground habitats could intersect with settlements, trade routes, and old infrastructure. They had not shown that every disturbance came from one source.
The following morning, Commander Rhea provided the team with a route chart leading beyond Frostgate. The northern road crossed a high plateau before descending toward a settlement called Windscar, known for its open-air markets and extensive network of caravan routes.
She warned them that Windscar had recently reported shortages of building stone and iron. With Frostgate's mine closed and Greyrock's ravine route blocked, the disruption was already spreading through the region.
Subin accepted the map and prepared to leave.
Before the team departed, he reminded Rhea to keep the eastern district closed until the survey was complete. She assured him that the instructions had been given to every guard and foreman.
The expedition passed through Frostgate's northern gate and began the climb toward the plateau.
Behind them, the town had recovered three trapped miners and stopped the immediate threat beneath its eastern wall. The Deepcrag Ravager was dead, but the old mine remained sealed, and the work of repairing Frostgate had only begun.
Ahead, Windscar awaited them with its crowded markets, disrupted trade, and another stretch of the northern route to cross.