The courtyard at Kasr Partox stank of oil and ozone, the kind of scent that clung to every fortress on Cadia. Morning light broke in jagged lines between the kasr's battlements, glinting off gold, ceramite, and the burnished armor of the Silent Sisters.
Aurelius stood at the center, voice steady, never raised above the clash of drill-blades and stubbers.
"Diamond holds. Corners move on the beat. Step two—three—four—lock."
Four Silent Sisters formed the moving points, their null auras grinding against the air, forcing nearby Guardsmen to fight through the faint mental ache. In the diamond's center, Cadian squad leaders coordinated their mixed units—Guard infantry, Sisters, and Mechanicus sappers with portable dampers—each move timed to Aurelius's clipped commands.
One squad faltered, breaking formation when a corner lagged. Aurelius didn't snap. He strode in, swapped the squad leader for a sharp-eyed trooper from the rear, and repeated the beat until the pattern held.
"The diamond is a doctrine, not a trick," he said. "Anyone here can run it. That is the point."
Seraphine Kest, helm under her arm, circled the diamond with her eyes narrowed. "Better," she said, voice like a blade drawn halfway. "Not yet good."
Aurelius allowed himself a faint smile. She was always stingy with praise.
The Alarm
The drill ended with the roar of a vox burst.
"Pylon Nine: shrine-hab district. Warp chant bloom.""Anchorworks: internal breach—ammo lifts seven through nine."
Two fronts. One clock.
Aurelius's mind split the moment he heard it. Pylon Nine was sacred ground and part of the pylon lattice itself—if a ritual inverted its harmonic, Cadia's entire anti-warp grid could falter. But the Anchorworks held the kasr's macrocannon feed lines. Lose them, and the outer kasrs would fall in hours.
He turned to Seraphine. "Take two diamonds to the shrine-hab. Break the ritual before the harmonic tips."
She nodded once. "And you?"
"The lifts." His gaze flicked to the underperforming squad. "Trial by fire."
Seraphine's Front — The Diamond in the Smoke
The shrine-hab's stained glass trembled before she even saw the enemy. The litany rolled through the hab-blocks like a hammer through iron, rattling teeth, pressing at the edges of her mind.
She snapped her hand in a pattern—four points of the diamond fanned out, Silent Sisters anchoring each, Guard squads filling the gaps. The air went still inside the formation, the chant's psychic teeth skidding harmlessly.
The Word Bearer Dark Apostle stood before Pylon Nine, draped in crimson, his armor etched with scripture. Around the pylon's cap, a phase-crown—blackstone plates bound in brass—slowly descended, its geometry grinding against the pylon's hum.
Seraphine moved her formation step by step, null-fields in rotation. Every shift cut the hymn's chord into harmless fragments. But the Apostle was quick—he pivoted the litany to target her movement, forcing her to hold one position too long.
A Sister went down to a bolter round from a choir balcony. Seraphine compressed her null-field into a razor-thin line, slicing the psychic pressure away from the pylon's crown just long enough for the replacement corner to lock in.
Aurelius's Front — Knives in the Machinery
The Anchorworks smelled of burned insulation and metal dust. Conveyor canyons and lift-chutes ran like veins, carrying shells big enough to level hab-blocks.
Aurelius pulsed Observation Haki in tight cones—rooftops, then conveyors, then gantries—each sweep no more than a heartbeat. He caught movement: a Cadian sergeant moving too smoothly, eyes too still.
The man dropped the disguise as soon as their eyes met—Alpha Legion, blade in hand. The duel was sharp and fast, Aurelius's gauntlet catching strikes, turning them into shoves that drove the traitor back.
"Three—two—take!"
His Conqueror's Haki flared in precise bursts, each timed to a Guardsman's fire order. Three heavy stubbers spoke at once, pinning Alpha operatives mid-feint, exposing the hex-runes shimmering on their armor. The leader—Venn—vanished into smoke, falling back toward the macrocannon control interlocks.
The Near-Inversion
In the shrine-hab, the phase-crown locked onto the pylon cap. Pylon Nine's hum detuned, vibrating the stones underfoot. Blackstone fought back, its resonance screaming in Seraphine's skull.
She could hold two steps of the diamond, no more. Over vox, Aurelius's voice came cold and exact.
"Green diamond, on her missing corners. Step when she steps. Now."
The green squad moved as one, filling the gaps in her pattern even as Aurelius's own battle roared in his ears. The doctrine held.
Belth's Gambit
Magos Belth's servo-mites scurried over the crown, planting inward micro-charges on three struts. One charge misread the lattice—armed outward.
Aurelius felt the pull—the temptation to flood the Anchorworks with Conqueror's Haki, freeze every man and woman in place until the work was done. But he'd trained for discipline.
"Three crews, three calls. Watch my beat."
One—two—three—detonate.
The crown imploded inward, blackstone shards falling like glass rain. The hymn stuttered into broken syllables. At that moment, Seraphine's pinpoint null spiked through the Alpha Legion's fallback hex-field, revealing Venn just as Aurelius arrived. One strike, and the traitor was down.
The Aftermath
The Dark Apostle withdrew into the warp-storm, but not before leaving a vox-line hissing in Aurelius's ear:
"Your wall sings a stolen song, golden one. Whose?"
Draeven himself signed the Diamond Protocol into kasr doctrine that evening. Guardsmen and Sisters alike saluted Aurelius and Seraphine—not as untouchable heroes, but as teachers whose method had worked.
Magos Belth approached Aurelius last, data-slate in hand. "The sub-crustal nodes beneath Cadia's pylons predate the pylons themselves. Blackstone is the interface. Something older built the source."
Beneath their boots, the ground hummed in a low, alien rhythm—matching the pylon's pulse for half a beat, then diverging.