Day 187: The first sign wasn't dramatic. It was simply wrong in a way Kai's body understood before his mind caught up.
Scout burst into the main chamber while Kai and Whisper reviewed supplies, moving with the tight, clipped urgency that meant the water specialist had found something the models didn't cover.
"Temperature's cycling," Scout said. "Not drifting—cycling. Hot pulse, cold pulse, like something's heating the deep water from underneath in waves."
Whisper's ears tilted. "That isn't a normal gradient."
"Nothing about this is normal," Scout said. "I've mapped these channels for months. This is new."
Within two hours, the evidence stopped being theoretical. The mineral profile of the upper seeps shifted. Whisper brought samples that tasted metallic, carrying the signature of deep-pressure systems that shouldn't be pushing up yet. Archive compared against ancient notes and his voice lost its usual warmth.
"The pH is alkaline. Mineral balance is wrong. It's like pressure from below is forcing deep water up," Whisper said, already running through implications. "The tremors aren't random anymore. They're rhythmic."
Kai felt it then, not through data but through the old instinct that lived under thought. This is how it started last time. This is what the stones meant.
The eastern seep reversed.
One moment it drained predictably downward. The next, it surged upward for seventeen impossible seconds, as if something in the dark had pressed a hand against the world and tested the fit. Then it settled, trickling as if nothing had happened.
Seventeen seconds changed everything.
"Something below is forcing water up," Scout whispered. "That wasn't drift. That was pressure testing stone."
Kai decided before Scout finished. "Full emergency assembly. Main chamber. Now."
Twenty-eight kits crowded under the vent light. Kai didn't soften the words.
"We evacuate to the surface bunkers. Not tomorrow. Today. We move before nightfall."
Silence pressed down.
"The bunkers aren't stocked," a young builder said. "We planned for weeks of transfer. You're asking us to abandon habitat and move into incomplete shelter."
"I'm asking you not to drown," Kai said. The old memory was shouting now, and he let the urgency show. "If rupture hits tonight, everything below becomes a trap."
Guardian stepped into the entrance like he had been standing by for this exact sentence. The warrior moved with calm economy, eyes already marking who could climb and who needed help.
"I'll form escort teams," Guardian said. "Primary route or secondary?"
"Primary if it holds. Secondary if we're forced."
Nest refused to move.
The comfort specialist had spent weeks turning raw stone into livable space for younger kits. He looked at the order like Kai had asked him to tear down his own den.
"I'm not leaving," Nest said. "This is home. I made it livable. I won't abandon it because water feels strange."
"Yes, you will," Kai said, not unkind, but final. "If you stay, you die. If you die, I spend strength grieving instead of protecting the others."
Nest's eyes widened, shock becoming hurt. "You'd leave me."
"I'd have to," Kai said. "I'd hate it. I'd still do it."
Bitey scooped Nest up without ceremony and carried him toward the route while he protested. She didn't explain. She moved like someone who understood that sometimes mercy wears a hard face.
"Sorry, Nest," she said anyway. "Mercy isn't optional. It just looks rough."
Evacuation became controlled chaos.
Construct—the builder who had helped drag an injured companion out of a recent cave-in—gathered supplies fast. The injured kit limped, still recovering from stress fractures.
"I'm not leaving him," Construct said when Kai pointed at the climbing shaft and the clock.
"You might have to," Kai said. "He may not make the ascent."
"Then I carry him," Construct said, as if the shaft weren't nearly vertical and the idea weren't almost impossible.
Shadow arrived already focused, thoughts braided with two others.
Let me help, he sent to Construct and the injured kit. I can dull the pain. Not sleep—just distance. It will feel like moving inside a dream.
"Will it hold?" Construct asked aloud.
"Probably," Shadow said. "We go now."
They started up. Archive ran logistics as they moved and the numbers came back harsh. Forty percent of food caches, if everything went perfectly. The rest would drown with the old life.
Whisper checked water containers and clicked in frustration. "Deep storage is becoming a maze. The table is fluctuating. We can't rely on it."
"Take what we can carry," Kai said. "Leave the rest."
"We're leaving medicine," Patch called, voice flat from knowing exactly what that meant. "The secondary cache is below a narrowing. We can't reach it safely."
"Leave it," Kai said, and tasted the failure without flinching. There wasn't time to feel it yet.
Guardian moved warriors like he was conducting something invisible. He checked the ascent, sorted climbers by need, and posted pairs at choke points.
"Primary holds," he reported. "Secondary has three blockages from the earlier collapse. Clearing them would cost an hour we don't have."
"Primary, then," Kai said. "First wave climbs unaided. Second wave with support. Guardian, you run that."
"Understood."
A younger kit froze at the sight of the shaft. The tunnel climbed into darkness and the body's logic said no.
Twitchy found him and did what Twitchy always did—but this time it helped. He checked the route out loud, one hold at a time, calm as counting prayer beads. One, two, three, check. One, two, three, check. The ritual became a ladder. The younger kit watched him verify each handhold and began to move.
"I check anyway," Twitchy said. "Now you know it's safe because I made it safe."
By the time the lowest rooms began to flood, the last groups were halfway up.
At the library chamber, Archive came running with a look that didn't fit his face.
"We can save twenty percent of the documentation," he said, clutching bundles of Whisper's scent-markers. "The stones stay. The embossed rubbings stay. The work stays."
Something gave inside Kai. He let it. Then he chose.
"Take portable cores," he said. "Patterns that matter now. We survive, or none of it matters."
Archive nodded once and took the future in his arms. The past stayed on its shelves.
Down the eastern passage, stone complained. Twitchy had checked it more than forty times, each faster and more desperate. Five minutes after he diverted a group to the northern path, the ceiling finally let go. Dust choked the world. The sound was like a bone snapping.
Three younger kits were trapped on the wrong side of the fall. Not buried—isolated.
Guardian didn't hesitate. He slid through spaces too small for comfort, found them by voice and dust, and shoved them back through the rubble as more stone fell. Ninety seconds. An eternity.
"They're safe," he said, bleeding from the shoulder and still assessing. "Northern route."
"Everyone to northern," Kai called. "Main path is compromised."
The detour added time they didn't have. It also turned catastrophe into a near-miss. The line held.
They climbed into thin light.