The first boarding torpedo struck like a thunderclap. Hull plating screamed as adamantine drills bit deep, carving through steel as if it were parchment. Sparks cascaded like meteors across the void-dark corridors before the breach exploded outward in a blast of fire and smoke.
From the smoke came the Mechanicus.
Red-robed enginseers, mechadendrites writhing like serpents, their vox-grilles chanting binharic prayers that rasped like corrupted hymns. Skitarii marched behind them in lockstep, galvanic rifles raised, augmetic limbs hissing with every precise motion. Servitors lumbered last, monstrous frames grafted with cannons and saws, their vacant eyes staring as weapons whirred to life.
"Cleanse the heretek!" the enginseers roared, voices amplified through vox-casters. "Scourge the soulless machine!"
The Arcadia's corridors erupted in violence.
Arcadian sailors charged with cutlasses and lasguns, meeting iron with flesh, faith with fury. Lasfire flashed in the mist, bolts slamming into Skitarii armor. One invader fell, but two more advanced, their eyes glowing cold green as they fired in perfect unison. Arcadian men screamed as galvanic rounds punched through their chests, burning holes clean through.
A servitor plowed through the melee, its hydraulic claw snapping a sailor in half. Another raised its grafted heavy bolter and sprayed shells that tore men apart in sprays of blood and shattered steel.
Still the Arcadians fought.
"Drive them back!" Thomar bellowed, his axe cleaving through a servitor's skull. Sparks burst as the machine-flesh hybrid toppled, but its bolter kept firing even as it fell.
For every invader slain, more poured from the breach. Their chants grew louder, filling the corridors with mechanical fervor. "Purity through steel! Purity through steel!"
The Arcadia herself reacted.
Black mist surged from the walls, blinding the enemy's augmetic eyes. Bulkheads slammed closed behind Skitarii squads, trapping them in crushing steel coffins. Lights flickered crimson, shadows stretching long, whispering in voices that only the invaders could hear.
But the Mechanicus pressed forward, undaunted.
An enginseer raised a mechadendrite tipped with a plasma cutter and carved a sealed bulkhead apart. Sparks rained as the door screamed open, the ship herself resisting. "You are no spirit," the priest intoned. "You are a blasphemy of unbound code. You will be broken."
A squad of Arcadian defenders were cut down as the Skitarii surged through.
And then Harlock stepped into the corridor.
His saber ignited in a hiss of lightning arcs, crimson eye glowing beneath the patch. He walked into the storm of galvanic fire as if the bullets bent around him. His blade flashed once, twice—Skitarri fell in pieces, sparks bursting as their augmetics were severed.
A servitor charged, saw whirring. Harlock's saber cut through it in a single stroke, the arc of power splitting steel and bone alike. The wrecked body fell sparking to the deck.
"Stand," Harlock said, voice carrying over the roar of battle. "This is your home. Make them bleed for every step they take."
The crew rallied, shouts echoing through the corridors. They threw themselves back into the fray, blades and lasfire flashing.
But this was no ordinary fight.
The Mechanicus were not raiders or mercenaries. They were zealots of steel and flesh, fighting with the discipline of machines and the fervor of priests. Every step forward was won in blood, every corridor contested.
And for the first time since the fall of their world, the Arcadians faced an enemy who would not break.
This was no skirmish.
This was war inside their very veins.