Read Chapter 1: Collision Course

The core sample was beautiful. Two meters of lunar regolith, layered like a frozen history book, each stratum a record of impact and silence. Elena Vasquez ran a gloved finger along the scanner readout, her breath fogging the inside of her helmet. The pale gray data scrolled past her visor's HUD.

Basalt. Anorthosite. A thin vein of something darker, almost glassy.

She zoomed in. That wasn't right.

"You seeing this, Control?" she said, her voice flat. "There's a vitreous layer at one-point-eight meters. That's not impact ejecta. That's not—"

The floor bucked.

It wasn't a tremor. Tremors were a slow roll, a ship settling on a bad mattress. This was a punch. The deckplate under her boots jumped, sending her sprawling backward against the sample rack. The drill arm above her shrieked as it twisted, hydraulic lines whipping like severed tendons.

Elena hit the deck hard. A red klaxon began to scream, strobing through the lab's observation window, painting the dust-caked glass in alternating sheets of crimson and black. On the far wall, the pressure gauge went from green to amber to a flashing, violent red in the span of three heartbeats.

"Control, this is Vasquez, Lab Seven. Explosion? What the hell was that?" She scrabbled to her feet, grabbing the edge of the console for balance as another shudder rolled through the structure. The lights dimmed, then failed entirely, plunging the lab into a darkness broken only by the emergency strobes.

Static hissed in her ear. Then, a clipped, automated voice: "Hull breach detected. Sector C. Pressure loss imminent. Emergency seals engaging."

Glass shattered somewhere to her left. The observation window—the one with the good view of Earth, hanging blue and small in the black—cracked along a web of fissures. Air began to whistle through it, thin and high, tugging at the loose sleeve of her environment suit.

Elena bolted. The whistle was a death knell. She'd run the breach drills a hundred times; everyone had. There was no time to grab the emergency oxygen pack bolted to the wall, no time to even think. Her hand found the door latch to the main corridor just as the emergency bulkhead slammed down behind her, shearing through a section of her sample rack like it was wet cardboard.

She stumbled through, into the corridor's gloom. The sirens were louder here, a physical pressure against her ears. Then another sound cut through: a heavy, grinding screech of metal on metal. The airlock door at the end of the corridor was closing, its thick blast shield descending with agonizing slowness.

And Jack Mercer was on the other side of it, running straight for her.

"Move, Vasquez! Move your ass!" He was a bull in a flight suit, all shoulders and momentum, a toolbag slung over one arm slapping against his thigh. His faceplate was up, and she could see the wild, frantic light in his eyes. Of course. Of all the people in this tin can, it had to be him.

Elena sprinted. Her boots clanged on the deck grating, her lungs burning. She was fast, faster than him in a straight line, but the shield was winning. Its massive edge was dropping, its hydraulic arms groaning under the strain. She was ten meters away. Eight. Five.

Jack dove.

He collided with her mid-stride, his momentum carrying them both into the airlock chamber in a tangle of limbs and padded elbows. Elena's shoulder slammed into the far wall. She felt the jarring impact shoot through her teeth.

The shield slammed shut behind them with a deafening boom of pressure, cutting off the sirens as if a hand had been clamped over the base's mouth.

Silence. A ringing silence, broken only by their ragged breath and the slow hiss of equalizing pressure.

Elena shoved Jack off her. "Get off me!"

He rolled away, already on his feet, his chest heaving. He looked past her at the sealed blast door, then at the red emergency light blinking on the inner control panel. "We're sealed in."

"No shit, Mercer." She pushed herself up, her shoulder screaming in protest. She ran a rapid, practiced eye over the airlock's status board. "Outer door pressure differential reading zero. Inner door... locked. We're not going back through that."

Jack was already moving to the outer panel, tapping at the manual release screen. "Then we go out."

"Out?" Elena stared at him. "Are you insane? The surface is a vacuous, radiation-blasted hellscape, and the last time I checked, our suits have about two hours of air. We're not suited for a walk. We were in the middle of a shift."

Jack didn't turn. His fingers were working the controls with a brutal efficiency she'd seen him use on the rover engines. "Worse than sitting in here while this airlock becomes a tomb? The breach was Sector C. That's the main habitat. It's blown. The base is venting. We're in a glorified closet, Vasquez. We either open this outer door and hope the repair station has a suit lock, or we wait to suffocate."

He was right. She hated that he was right.

The outer door was a solid slab of steel and composite, designed to withstand micrometeorite impacts and the ninety-second, near-absolute-zero cold of a lunar night. Its manual release was a mechanical crank, buried in a recessed panel, meant for emergency use only. Jack yanked it open and grabbed the handle.

"It's jammed. The blast must have warped the frame." He grunted, hauling on the crank. It didn't move. He planted a boot against the bulkhead for leverage, his muscles corded under the thin fabric of his flight suit. The metal groaned, a low, resonant protest, but refused to give.

"Let me try." Elena moved past him, pushing his hands away from the crank. She examined the mechanism, her mind clicking through the schematics she'd studied for the base's certification exam. "The linkage is likely bent. If you force it, you'll snap the pin. We'll be sealed in for good."

"Then how do we fix it?" His voice was a growl, clipped and impatient.

"We don't fix it." She reached into the toolbag he'd dropped, her fingers finding a heavy-duty wrench. "We bypass the linkage. There's a shear bolt here, holding the main strut to the door frame. If I can pop it, the door's weight might be enough to swing it open on its own."

"What about the pressure seal? You pop that bolt, you compromise the integrity. We'll be exposed to vacuum before the door even moves."

"We'll be exposed to vacuum anyway, Jack." Elena met his gaze. The look she gave him was pure ice. "The question is whether we choose the moment. So, do you want to live, or do you want to argue with me?"

Something flickered in his eyes. Not anger, exactly. A grudging, wary respect. He stepped back. "I'll brace it. You pop the pin."

She wedged the wrench against the bolt's head and put her weight into it. Nothing. She repositioned, cursing the slick gloves. Then, with a grit of teeth, she swung the wrench back and slammed it forward. The impact jarred her arms to the elbows. The bolt held.

"Again," Jack said. He'd found a spare piece of pipe and was jammed between the door and the frame, his body a brace.

Elena hit the bolt again. A screech of tortured metal. A creak. The door shuddered, a hair's width of black space appearing at its edge. A thin, silvery jet of escaping air sprayed from the gap, freezing instantly into a plume of frost crystals.

"Seal's compromised!" Jack shouted, but he didn't move. He pushed against the door with a roar of effort, veins standing out on his neck.

Elena ignored him. One more hit. The bolt snapped with a sound like a gunshot. The door's massive weight, now unbalanced, began to swing outward on its own, pulled by the great, yawning emptiness of space.

The air in the lock began to howl. Frost exploded across every surface. Elena felt the air ripped from her lungs, a violent, drag-like pressure on her chest. Her ears popped agonizingly. Spots danced in her vision.

Through the freezing chaos, she saw Jack. He'd been thrown clear, tumbling toward the widening gap, his gloved hand scrabbling for a handhold on the smooth inner wall. There was nothing to grab. He was sliding, his boots losing traction on the ice-covered deck, his body being sucked out into the black.

No. Not like this. Not because of a stupid, jammed door.

Elena's training took over. Her arm shot out, snagging the coil of safety line clipped to the wall. She snapped it to her own suit's harness, then pivoted, bracing her feet against the inner door's frame. She looped the other end around her arm, once, twice, and hurled it at him.

It spun through the air, a silver blur. Jack's hand snapped out instinctively, catching it. The line tautened with a violent jerk, nearly ripping Elena's arm from her socket. She screamed, a raw, guttural sound lost in the roaring wind as her boots slid six inches across the metal.

But she held. The line held.

Jack pulled himself hand over hand, back into the airlock, his face pale, his breath coming in panicked, ragged gasps. He collapsed against her, and they both slid down the wall, chests heaving, as the last of the air bled out into the void.

Silence. Absolute, crushing silence.

The outer door hung open. Above them, a sky of impossible black, pricked with unblinking stars. Below, a sea of gray rock, cast in harsh, shadowless light. The Moon.

Elena pushed Jack off her and checked her wrist HUD. Air: 87%. Time at current consumption: approximately one hour and forty minutes.

Her heart was hammering so hard she could feel it in her throat.

Jack looked at her, his faceplate frosting over from his own ragged breath. "You saved my life."

"You cost me a perfectly good sample," she said, her voice trembling despite its bite. She looked out at the vast, deadly stillness. Then she looked back at the sealed, unyielding door behind them.

They were no longer inside Moonbase Copernicus. They were on the surface of the Moon, with a dwindling supply of air and no way back in.