They hit Floor 172's portal running and didn't stop.
Marcus had Ren over his shoulder in a fireman's carry, one arm locked across her legs, the other holding his shield flat against his back. The marine moved at a pace that should have been impossible with a hundred and forty pounds of unconscious Pathfinder across his frame. He moved at it anyway. The body doing what the mission required because a woman was dying and the clock Marcus was tracking against her pulse said they had three hours and change to cover thirteen floors.
Floor 172. Supply floor. The cache with the substituted compounds still sitting in the northern alcove. Thirty-seven seconds portal to portal.
Floor 171.
The combat chamber was supposed to be empty. They'd cleared it on the way up. The Tower had restocked it.
Fourteen constructs. Fresh deployment. The real-time iteration engine had watched them fight through this room three hours ago and built a response.
"No engagement," Maya said. "Corridor route. East wall."
The party ran the eastern edge. Constructs tracked them, blade limbs extending. Marcus put his shield between Ren and the nearest one without breaking stride. The impact rang through the compressed room. Kira killed the one that got ahead of them — a single cut, the construct dropping, the Afterimage already at the exit portal.
Through. Floor 170's transition corridor.
"Time?" Maya asked.
"Eighteen minutes since we left 173," Marcus said. The marine tracking the clock against Ren's four-hour window. "Three hours forty-two minutes remaining."
"We need to average one floor every seventeen minutes to make it."
"We averaged one floor every twenty-eight on the way up."
"Then we go faster."
Floor 170.
Noah stopped in the portal frame.
The endurance chamber had lost four meters on every wall since they'd rested here. The sixty-meter room on Soren's map, already shrunk to fifty-something on the ascent, was now forty-two meters across. The ceiling had dropped. The warm air was hot air now, the substrate radiating heat that made the room feel like the inside of an engine.
Three hours ago, the migration had been a process measured in months.
This wasn't months.
"It accelerated," David said. His hand was on the corridor wall and his face was the color of old concrete. The mage who listened to the building's substrate the way sonar listened to the ocean, and the ocean had just changed its tide. "When Noah activated on 173. The thing in the container responded. The response sent energy through the substrate. The construction process sped up."
"My activation did this?"
"Your activation gave it something to respond to. The response fed power into the construction." David pulled his hand off the wall. His fingers were red. "The migration that was happening over months just happened in hours."
Noah looked at the shrinking chamber. He'd wanted to know if the thing could reach him. The answer had cost the building five floors' worth of structural integrity.
"Move," Maya said. No recrimination. She processed guilt as wasted calories and spent her energy on the problems she could still solve.
The endurance chamber had restocked. Constructs deploying from the portals, the seventy-second wave timing cycling. The party ran the perimeter. Marcus's shield caught two impacts. Emma's barrier deflected a third. They didn't fight. They ran.
Floor 169. Fourteen constructs, restocked. The room was two meters narrower than on the ascent. Maya's displacement threw the closest construct into the far wall. Marcus took a blade across his vambrace. The armor held.
"How's Ren?" Noah called.
"Pulse weaker. She's burning calories faster than her body can sustain." Marcus didn't slow down. "The Path Sight process is eating her alive."
The golden shimmer at Ren's hands was visible even slung over Marcus's shoulder. The stuck activation. Her fingers twitched against his back.
Floor 168. Supply floor. Twenty-nine seconds.
Floor 167.
"Bypass," Noah said. "Soren's map. Western corridor, behind the second alcove. Maintenance passage straight to 166's transition corridor."
Maya looked at the combat chamber entrance. Eighteen constructs visible through the portal shimmer.
"Take it."
The passage was behind a substrate panel in the western alcove. Noah found it by feel, running his hands along the wall until the density changed. He pushed and it gave.
Tight. A meter and a half wide, two meters tall. Marcus angled Ren's body to fit, her legs catching on the walls.
The substrate was hot. Not warm. Hot. The passage walls radiated heat that made Noah's skin prickle, the material actively migrating, loosening and flowing upward. In another few months, this passage would be sealed shut.
They pushed through. Single file. Marcus and Ren first, then Maya, then David, then Noah, then Emma.
Emma was last.
She hit the passage wall and her whole body seized.
The amber energy at her hands flared. Not the controlled deployment of her barrier ability. The involuntary activation of the deal mechanism, the collection protocol firing in response to her moving a burned-out Pathfinder away from its destination. The protocol had been pulling since Floor 173. Pulling toward the container. Pulling upward.
Moving downward through the bypass, twelve floors below the container and descending, the protocol punished the distance.
Emma's legs locked. Her hands pressed flat against the hot walls and the amber energy crawled up her forearms. Her body wanted to turn around. The deal installed on Floor 12 had a secondary function and the secondary function was screaming.
"Emma." Noah was two meters ahead of her. He turned in the tight space, his shoulders scraping the walls.
"I can't—" She bit down on the word. Her teeth found her lower lip and pressed until blood welled. The pain cut through the compulsion, two seconds of motor control that belonged to her instead of the deal.
She moved. One step. Two. Bloody prints on the hot substrate.
Noah reached back and grabbed her arm. Pulled. She came forward stumbling, her balance wrong because the protocol was orienting her body toward a destination behind and above them.
"Don't let go," she said. The fast cadence stripped to three words. Her lip was bleeding freely, the blood running down her chin, and her eyes had the wide focus of someone fighting a war inside her own nervous system.
He didn't let go.
They cleared the bypass. The passage had saved six minutes. It had cost Emma a piece of her lip and something else Noah couldn't see but could feel in how she leaned into his grip.
Floor 166. The walls were still moving. The room was smaller. They ran the edge. Maya displaced. Kira cut. Marcus absorbed.
Floor 165. Puzzle floor. The thirty-minute timer appeared.
"Skip it," Maya said.
The penalty for non-completion was a thirty-second lockout on the exit portal. They waited. Thirty seconds that felt like thirty minutes. Ren's golden shimmer pulsing against Marcus's back. Emma pressed against the wall, bleeding from her mouth, the collection protocol pulling at every joint in her body like wire threaded through her bones.
Through.
Floor 164.
Ren woke up.
Not gradually. She went from dead weight to rigid in one second, her body jackknifing, her hand shooting out and catching Noah's arm with a grip that had no right to exist in a woman whose metabolic reserves were crashing.
Marcus went to one knee. Had to. Her movement had shifted his center of gravity.
Her eyes were open. Bloodshot. The golden shimmer at her hands surged. She was looking at Noah. Through Noah.
"It knows your frequency now." Her voice was a rasp. Sandpaper on stone. "It tasted your Path Sight. When you activate again, it won't just look."
She pulled him closer. Her grip on his arm was leaving bruises.
"It'll hold."
Her eyes rolled back. Her hand released. She went limp and her breathing dropped to the shallow rhythm of a body that had spent its emergency reserves on four sentences.
Marcus stood. Kept running.
Noah ran beside him. His arm ached where Ren's fingers had dug in. The words sat in his processing like a runtime error that wouldn't clear.
*It'll hold.*
One second of contact on Floor 173. One second of a face made of golden lines. And now it knew his frequency the way a predator knew a scent. The next activation wouldn't be observation. It would be capture. His enhanced Path Sight, with the 4.5-multiplier range and the broadcast signature detectable four floors away, would give it a stronger channel than Ren's degraded ability ever had.
Floor 163. Floor 162. Floor 161.
The floors blurred. Construct formations skirted, outran, displaced through. Maya's reserves burning. David grounding electrical discharges on Floor 162, absorbing construct death-bursts that arced toward Marcus and Ren. Kira killing whatever got too close, every cut designed to create space rather than destroy.
Emma walked the last three floors with Noah's arm around her waist.
The collection protocol had stopped being a pull. It was a scream. Her amber energy flickered constantly, the deal mechanism hijacking her system's output. Her steps were wrong, her body fighting itself, motor control split between her will driving downward and the mechanism driving up. She'd bitten through her lip on Floor 162. Blood drying on her chin.
She was losing. And she kept stepping. Each floor's portal a negotiation between her legs and the thing that wanted them pointed in a different direction.
Noah held her up. His sister. The woman who'd been selling information about him to the Tower since Floor 12 and who was now bleeding from her face because she refused to be its delivery system. He held her and she walked and neither of them spoke because speaking would have cost energy that neither of them had.
Floor 160.
The portal opened on Soren's base.
Vanguard medics reached Marcus before Maya finished saying "Pathfinder down." Two of them took Ren from his shoulder with the coordinated efficiency of people who treated casualties on a schedule.
"Continuous Path Sight activation," Marcus told them. "Four hours from collapse onset. She needs the full compound protocol."
They carried Ren toward the medical alcove. The golden shimmer at her hands followed her, the ability running its infinite loop even as her body shut down around it.
Soren was standing at his map board. He watched the party come through the portal — six climbers who'd left twelve hours ago and come back carrying intelligence that would rewrite everything.
"You found her," Soren said.
"She found us." Maya's voice was hoarse. The Void Walker who'd spent her displacement reserves clearing a thirteen-floor retreat at dead sprint, who'd kept six people alive across thirteen restocked combat floors by displacing threats she could barely see through her own exhaustion. "We have information. It changes what you know about the construction. It changes what everyone knows." She looked at Soren. "Tomorrow. Tonight, my people rest."
Soren's jaw worked once. The same gesture he'd made when Maya had corrected his terms before they'd left. Then: "Tomorrow."
The party found wall space along the base's eastern corridor. Marcus sat first, his legs giving out with the controlled descent of a man who'd carried a hundred and forty pounds across thirteen floors. He leaned against the substrate and closed his eyes. David sat beside him, hand on the wall, listening to the building.
Kira stood at the portal. Looking upward through the architecture toward a man climbing alone who didn't know what was waiting.
Maya stood with her back to the corridor wall, her eyes on her party. Counting. All six present. No one lost.
Noah sat against the eastern wall. His hands were shaking. The same tremor from Floor 173, the motor response of a body that had been seen by something it couldn't see back. He thought about closing them into fists and decided not to. The shaking was honest. Let it shake.
Emma lowered herself beside him. Stiff. Mechanical. The collection protocol still firing even here, twelve floors below the container. Her lip was split and crusted. Her amber energy flickered once at her fingertips and went still.
She was looking at the ceiling.
Noah reached out and took her hand.
She squeezed back. Hard. The grip of someone holding on to the one thing the mechanism couldn't make her let go of.
They sat against the wall of Soren's base on Floor 160. They didn't speak. They didn't let go.
