Ethan drifted up through layers of muffled sound and stale suit air. He tried to remember if there'd ever been a moment in his life when darkness felt this absolute. The HUD lay dead without the soft pulse of suit telemetry or the faintest shimmer of reflected light. He opened his eyes to find the world still sealed behind an impenetrable black like a blindfold pressed against his skull. His breath rasped inside his helmet and echoed back at him as a hollow sound.

  The suit vibrated weakly at his ribs as its degraded systems forced a warning through.

  [PWR: 10% | Critical Reserve Mode Engaged]

  The letters flickered against nothingness and left more darkness in their wake. The HUD panels, map, and compass line remained dead. The readout might as well have been the last twitch of a dying limb.

  He lay still and tried to separate his own heartbeat from the ringing in his ears. Every sound felt distant and strangely padded like he was underwater. He wasn't sure if he'd been unconscious for seconds or hours. The memory of the explosion came back in broken shards of heat and pressure. The world had folded under him.

  Boots scraped over stone somewhere in the distance. "Ethan?"

  The voice was faint but unmistakably human and imminently unforgettable. It cut through the fog in his skull and sounded impossible. But no. It couldn’t be her, right? She couldn’t really be here?

  He squinted but the dark felt too perfect and final for anyone else to be there. His throat tightened. He wondered if this was the last hallucination of a dying mind.

  "CelestOS." His tongue felt thick against his teeth. "Sanity check."

  A lag and hesitation followed before the AI’s voice arrived. It sounded bright and irritatingly chipper like a corporate mascot dragged into a funeral.

  CelestOS: Auditory inputs authentic. Biometric signature match: High. Note: User heart rate is entering ‘cardiac arrest’ territory from excitement. Please regulate your breathing.

  He almost laughed. His voice came out rough and shook with disbelief. "That's... that's not possible."

  Something touched his shoulder before CelestOS could reply. The contact felt firm and human. Ethan jerked so hard that pain shot down his spine, but the grip tightened just enough to steady him. It was the familiar texture of a glove rather than the cold clamp of a creature or resin. He recognized the fabric over reinforced knuckles. "Ethan, it's me," the voice said again. It sounded closer now, warm and strained. "Stay still. You look like hell."

  “Maria? How. What?” His breath stalled in his chest. "I can't see anything. How are you—"

  "NVGs," she said. "Hold on."

  He knew that voice and tone too well to doubt them for more than a heartbeat. Every part of him trembled while adrenaline clashed with the desperate disbelief tightening behind his ribs. He tried to lift a hand to reach for her, but his arm felt heavier than the suit plating. She pulled him into her arms.

  She wrapped one arm around his shoulders and the other around the back of his helmet. Her suit pressed against his to create warmth where their bodies met. His fingers curled in the fabric at her side like he needed proof she wouldn't vanish if he let go. Six months of nightmares collapsed into that one breath where he felt her exhale against him.

  He leaned forward without thinking. She met him without hesitation. Their helmets brushed before the glass slid away and their lips met in the dark with a frantic urgency that bordered on painful. It was raw survival instinct crashing into relief rather than anything clean or romantic. Their breaths tangled while their hands clutched wherever they found purchase. Ethan clung to her like pressure and gravity finally made sense again. How was she here?

  They stayed locked together in the pitch black long enough for the ringing in his ears to soften into something like quiet. Her gloved hand stayed on his cheek when she finally pulled back. She steadied him like the dark might swallow him again if she moved too fast.

  As suddenly as it had begun, the moment ruptured. A deep and rolling thunderclap shook the cavern. The vibration hit the stone before hitting his body and the air in a delayed shockwave that rattled inside his ribs. Ethan felt Maria’s arms tense around him a split second before the next roar tore down the tunnel. It was a pressure scream made by too much mass moving fast through a tight space. The sound pulverized the silence and made his teeth ache.

  Maria shifted her grip. Her hand slid down his arm until her fingers wrapped tightly around his wrist. "We have to move," she said. Her voice was sharp with the clipped discipline he remembered from a lifetime ago. "Follow my voice. Don't let go of my hand."

  Ethan obeyed. The darkness felt heavier with every second and pressed in from all sides as though the cavern itself was inhaling. Maria tugged his wrist. He lurched to his feet. His boots scraped against debris he couldn't see, and the movement sent a burst of white pain through his shin where he'd hit the base's stone earlier.

  Another crash boomed behind them. Something enormous collided with the cavern wall again and shook loose grit that peppered Ethan’s helmet. The monster’s roar followed a moment later. It was wet and resonant enough to rattle his chestplate. It sounded closer. Maria pulled harder. Ethan forced his legs to work. He trusted the invisible ground beneath him and the warm pressure of her glove guiding him forward. Every step felt like running through a void. He had nothing to judge distance or direction. The only reality he had to cling to was the movement of her hand and her voice calling back to him over her shoulder. "Left. Step over that. Watch your footing."

  Stolen content warning: this tale belongs on Royal Road. Report any occurrences elsewhere.

  His lack of sight didn't matter. He believed every word. Something shifted in the darkness behind them. It was a scrape and a thick splash that echoed like a body hitting water. Maria reacted instantly. She pulled him sideways and slammed his shoulder into a natural column he couldn't see. She drew her weapon one-handed.

  She fired blind into the dark. The shot cracked like a hammer strike. Stone chips showered the floor. The monster screamed in response while its cry distorted into a low gurgle that rumbled down Ethan’s spine.

  "That slowed it," Maria said. She yanked him away from the column before it could collapse. "keep Moving."

  They sprinted again. Ethan stumbled on uneven rock, but Maria caught him by the elbow and jerked him forward without breaking stride. The roar behind them shifted in tone. It sounded angrier and higher. He imagined spraying feelers or sonar pulses rippling through the cavern to search for their shapes in the dark. Air pressure changed ahead of them. Ethan felt the faint rush of wind through a narrower space before he heard anything. Maria dragged him toward the Living Wall tunnel entrance. He recognized the pressure drop as the breach he had carved days ago. It was the one place the monster's bulk couldn't easily follow.

  "Almost there," Maria said. Her breath cut fast through her mic. "Don't let go."

  He held on. He tightened his grip until the bones in her hand pressed into the glove. Another crash echoed. A chunk of ceiling cracked off behind them and shattered on the ground where Ethan had just stepped. Maria didn't slow. She pulled him harder and dragged him through the pressure shift into the narrow tunnel mouth. The darkness somehow grew tighter as the cavern opened into the enclosed passage. The sound of the monster dulled the instant they crossed the threshold. Ethan's breath rasped with fatigue while his heartbeat hammered in his ears. Maria stopped long enough to steady him.

  "We're safe from it for now," she said. "But keep your head down. It might try a pressure surge at the opening."

  Ethan nodded even though she couldn't see it. The tunnel was pitch black and suffocating in its narrowness. He felt the temperature stabilizing. The air turned cooler and stiller. They had escaped for the moment. Maria kept her hand around his and guided him deeper into the tunnel's protective dark while the monster's distant roars rolled against the stone behind them. They were close enough to remind him how narrow their margin had been.

  The roar came first. A low and underwater detonation rolled through the cavern and made the ground lurch beneath Ethan’s boots. Maria’s grip tightened on his arm to steady both of them as pebbles skittered across the floor. The sound that followed was worse. A wet and resonant howl vibrated inside Ethan’s helmet until his vision pulsed with static he couldn't even see. Maria reacted instantly. She pulled his wrist up against her chestplate. "Ethan, we have to move. Stay on me."

  She dragged him forward before the echo had fully faded. Ethan stumbled after her. His legs felt heavy and unbalanced. Every shift of his weight felt like stepping into the unknown. Every breath carried a new edge of panic that he couldn't shake. Without lights, he could've been running toward a cliff or the monster itself. His boot hit a patch of rubble, and he pitched forward. Maria hauled him upright with a steady but strained grunt. And then she stopped. Abruptly.

  "What the fuck is this place? We’re back at the lake!" Maria said. "Come on or they’ll catch us!"

  She tried to pull him in a new direction, but Ethan pulled up short.

  "Maria," he panted. "I know this place. I think I can get us out of this section."

  She didn't slow. "You can't see, Ethan."

  "If we’re at the lake, then we can get to my base." Another tremor shook dust loose overhead. "I can get us there."

  Maria skidded to a stop just long enough for him to feel her turn toward him. Her free hand reached up to unclip something from her helmet and press it against his chest. "The NVGs," she said. "Take them. I'll follow you."

  He fumbled for the straps until her hands found his and guided them into place. The goggles were warm from her body heat. When he pulled them down, the world snapped into eerie clarity. He saw glowing outlines and drifting dust motes illuminated like ash. Maria stood close enough for him to see the tight focus in her eyes. The next roar hit the cavern before he could speak. The monster slammed a bulk of impossible size into the far wall. A wave of air pressure swept across them. Ethan saw stone fracture in a jagged line. The creature was hunting.

  "Alright," Ethan said. He gripped her hand and steadied himself. "Follow my steps exactly."

  He pulled her into a run and dodged a collapsed yet half exploded monster he wouldn't have known existed seconds earlier. The NVGs made the world look thinner and more brittle. He could see enough to navigate. Maria followed close. Her boots matched his pace. Behind them, something thick and serpentine scraped along the floor. The creature lunged again a second later. It slammed into stone with enough force to warp the air itself. Ethan felt the concussion through the soles of his boots.

  "Almost there," he said. "Ten meters."

  A column loomed ahead. He ducked under it. Maria mirrored him in one fluid motion. Another roar rumbled behind them. The creature’s echolocation pulses flicked dust from the ceiling because it knew they were moving. Ethan saw the breach. It was a jagged slit in the cavern wall where his Auto-Pick had once torn the resin apart. The tunnel beyond it looked like a black throat swallowing the light. "Jump," he ordered.

  They dove together. The tunnel swallowed them. The sound of the monster dulled instantly. The air grew cooler and tighter around them.

  The tunnel cramped around them like a throat closing after a scream. Ethan steadied himself with one hand braced against the rough wall while the Night Vision goggles painted everything in thin and wireframe green. The air tasted cleaner and familiar here. It tightened something in his chest. They had made it to his section. His base was close. "Keep moving," Ethan said. "Generator's not far."

  Maria squeezed his forearm in acknowledgment and stayed behind him to match his steps. The NVGs cast her as a lean silhouette with dented armor. He heard her ragged breathing from the sprint. He couldn't focus on her yet. They needed to be safe. The darkness needed to stop feeling like a hand pressed over his mouth. The tunnel widened. Stone gave way to a smoother floor where he had once run conduit lines. The place felt dead without their hum. Ethan reached the threshold of his base and halted. The chamber stretched before them. It was barely visible through the faint phosphor glow. Machinery loomed like hunched skeletons. Conveyor belts hung motionless in the air. The forge sat cold and silent against the far wall. The generator stood in the center like a gutted carcass. The base was cold, dead, and silent, but by some unknowable miracle, he’d achieved his mission. He’d found Maria.