Chapter 73: End the Disorder
"Defensive formation!"
At Casiel's command, the Astartes went back-to-back in a circle instantly, placing Duvette's four at the protected center. They understood the value of the Commissar.
The Munitorum Administrator who had emitted the shriek had fulfilled their final purpose. The grotesque smile still on their face, the body folded and went down to the floor.
The swarm came in the next moment.
The defensive battle that erupted was immediately and absolutely brutal.
From cracks in the ceiling. From behind the stacked containers. Hybrid cult members in their dozens, large mutant bodies wielding heavy mining tools, and purebred Genestealers by the score — they flooded in from every direction like a dam wall coming down at once, crashing into the isolated squad with the indifference of a natural event.
The boltguns in the confined underground space merged into a single continuous roar.
The Astartes held the tight circle. Every volley tore a gap in the alien tide. Every gap filled back in immediately with more bodies pressing forward.
In the meatgrinder grinding of that kind of combat, what Duvette hadn't expected was this: through the rotation of the formation, Casiel and all seven of the Seventh Company veterans were deliberately and consistently using their massive power-armored bodies to cover him at the circle's center.
The Ultramarines were nothing if not pragmatic. They understood clearly that in an underground nest where sight lines were gone and every dark space was an ambush waiting to happen, Duvette's near-prescient tactical awareness was the only working sensor they had.
Keep the Commissar alive and nothing could take them from behind.
And Duvette earned every gram of that protection.
His eyes fixed on the Strategic Display without wavering. He put bolt rounds precisely into the approaching cult members one at a time. His voice, already worn rough, he drove to its maximum volume.
"Nine o'clock, ventilation duct! Four purebreds moving through it!"
"Chaplain Casiel — the drainage grate at your feet!"
Under the constant, precise guidance of Duvette's warnings, the Astartes pre-empted every ambush attempt before it could land, shattering the attackers while they were still in the approach.
Maintaining the concentrated rate of fire, the group began a slow and deliberate fighting withdrawal toward the main corridor under Casiel's direction.
Casiel's intent was clear: enemy numbers had far exceeded any reasonable estimate. The only viable outcome was a complete withdrawal to the surface, followed by demolition charges brought to bear on the entire underground structure, sealing whatever was down here beneath collapsed rock permanently.
They had barely managed to fight their way back into the main corridor when the situation shifted entirely.
The roar that came from the darkness at the corridor's deepest end was not a sound that could be easily categorized. It carried psychic weight and raw, savage fury in equal measure and it hit the narrow stone space like something physical. Dust fell from the walls. The air seemed to acquire a texture — something suffocating and absolute that had no natural explanation.
Duvette's eyes went straight to the Strategic Display.
A contact point of absurd size was moving toward them. At a speed that had no relationship with what a creature of those dimensions should physically be capable of. Crushing through everything in its path without slowing.
The true master of this nest. A Genestealer Patriarch that had been alive for longer than anyone in this corridor could accurately count.
"That is the Patriarch!" Duvette's warning came sharp and immediate. "We must withdraw now! We cannot engage that!"
Before the last word was out, a massive shape tore through a heap of construction materials at the far end of the space and came into view.
Nearly four meters of it. Body armored in layer upon layer of thick chitinous plate. Four arms, each one thicker than a human waist, ending in rending claws that curved like scythe blades. The skull was a convergence of insect and reptile anatomy at its most hostile, compound eyes burning with intelligence and malevolence.
The Patriarch.
It produced another roar that drove the surrounding Genestealers into a frenzied escalation and then broke into motion itself, moving toward the formation at a speed that had no business belonging to something that size.
"Withdraw! Maximum speed!" Casiel's order came at full volume.
The circle formation converted instantly to a breakout column. Two Astartes at the front, boltguns and chainswords clearing the path. Casiel and three others covering the rear. Duvette's four in the protected center.
They drove into the corridor. The Patriarch and the tide of Genestealers came after them without pause.
The corridor's width constrained how many could press them at once, but it made the withdrawal no easier. Genestealers kept dropping from ventilation ducts ahead to block the route. Behind them, the Patriarch's roar and the impact of its footsteps against the floor grew louder with each second.
"It's gaining!" Stroud looked back and called it out.
Duvette could feel the pressure of it less than thirty meters behind. Then without warning, a massive and icy psychic force hit the entire group like a wall of solid matter — a Warp-borne assault that came directly from the Patriarch.
The mortal veterans stumbled. Even the Astartes showed a fractional slowing.
With the exit to the surface only the last few dozen meters ahead, at the most critical moment of the entire operation, Duvette called the last card he had been holding.
[Silence] — activate.
An invisible wave radiated outward from him as its center, carrying something that felt like absolute order imposing itself on the surrounding space. Under its effect, the Patriarch's terrifying Warp-borne psychic pressure dissolved — completely, instantly, the way snow dissolves when the sun reaches full strength.
Every mind in the corridor cleared to absolute precision in the same moment. Fear and the sluggishness the psychic assault had produced were gone entirely. Thirty seconds of total psychic vacuum. Thirty seconds that would determine who walked out of this tunnel and who did not.
The Genestealers relying on the synaptic network for coordination fell into complete confusion the instant the link severed. They circled in place without purpose and began colliding with and tearing at each other, the hive mind's direction replaced by nothing at all.
The ordinary cult members cried out in terror. The synaptic network's conditioning, which had blinded them to the nature of their own existence, had been stripped away with it. For a brief moment they seemed to perceive what had always been concealed from them. They froze where they stood. Then, amid screaming, the purebred Genestealers they had once worshipped as angels consumed them entirely.
"Move!" Duvette's voice was a low, hard command.
Everyone ran at their best speed through the corridor. Their footsteps rang in the sudden, complete silence.
When they burst through the first staircase and reached the metal door at the basement level, [Silence] expired.
Behind them, the Patriarch's roar returned at greater intensity than before, and the sound of the pursuing tide rolled up the stairs. But the distance was sufficient.
"Out! Now!" Casiel drove the metal door open.
They came out of the building intact.
Casiel's armor was damaged in several places — the marks of what they had survived underground were written plainly across its surface. Behind the skull faceplate, the eyes burned.
"Seal this location! Every alien that emerges is killed on the spot!" He turned to the Magos Biologis and the auxiliary troops already locked into position around the building and issued the order that had no revision available.
"Contact the orbital bombardment vessels. Authorize the lance array at minimum output. Burn through this building's foundations. Destroy everything below it. I want them buried alive in their own tomb." His voice carried nothing but controlled fury.
He looked at the Magos Biologis. "How long to run genetic screening on all ground forces?"
"With current personnel, approximately one standard Terran month."
Casiel made a sound that was not pleasant to hear. Not enough.
Duvette spoke. "Screen the bald individuals first. And anyone presenting unusual skin pigmentation. These are the most consistent external markers. I also recommend extending the screening to fleet personnel. If the enemy has infiltrated the ships, the damage they could cause in the engagement ahead would be incalculable."
The Magos Biologis's optical sensors turned toward Stroud.
The bald man raised both hands. "Don't look at me. I am entirely loyal."
Casiel nodded. "Follow the Commissar's recommendation."
The Magos Biologis turned and departed.
Duvette let out a slow, long breath. The disorder on Parmenio was approaching its end.