Darkness.
A darkness with a physical weight enveloped everyone.
At this moment, Sibylla and the team she led had stepped into the Underhive of the Eternal City.
As it turned out, much like the eighteen levels of hell in myth, the scene here was far worse than the peripheral slums seen earlier. It was a malicious labyrinth formed by countless massive discarded panels, broken pipes, collapsed trusses, and rusted wreckage, haphazardly stacked over thousands of years.
Everyone's vision was nearly obscured by the omnipresent industrial dust. The dim glow of light sources appeared weak and powerless here, barely illuminating a few steps ahead, while anything further was swallowed by devouring blackness. In many places, what were called "roads" resembled the tangled, chaotic veins of some dying titan, knotted together and nearly impassable.
Without a doubt, this environment was a nightmare for any attacking commander, enough to plunge even the most elite troops into the desperate situation of fighting isolated battles. Yet, for the xenos who had long since adapted to the darkness, this was their home turf. They could launch attacks from any angle, pushing their advantages of numbers and terrain to the limit. Even enemies stronger than them often had to pay a price in blood here—much like a certain Blood Angel who had once suffered a near-total wipeout in a similar environment.
However, the current situation was different from the past.
At the edge of every Tempestus Scion's tactical visor, a ghostly blue cursor flickered, and a concise panel silently popped up:
[Mission: Hidden Operation]
[Time: 891.M41, 11:12 AM]
[Location: Terra Prime, Eternal City Underhive]
[Objective: Eliminate threats from Genestealers]
Almost at the exact moment all soldiers finished reading simultaneously:
Hiss... sizzle...
A flood of noise surged from all directions, faint at first, then becoming dense and surging. It was the sound of sharp xenos limbs, chitin grinding violently against metal within the various ventilation ducts. The sounds layered upon each other, converging into a skin-crawling tide, like some massive crawling organism eager to devour the prey that had intruded upon it.
"Heh."
Over the channel, Sibylla let out a clear, cold snort. Every Tempestus Scion silently adjusted their grip on their weapons, the gaze behind their tactical visors as sharp as ever.
Squelch!
The muffled sound of a blade cutting into flesh rang out. A heavy Scion warrior lunged forward, his power sword tracing a cold arc of light, slicing a hybrid Aberrant leaping from a side pipe into two pieces. He used his steadily raised storm shield to block the spray of thick purple blood. The transition from defense to offense happened in an instant; he leveled his melta pistol, and a flash of incandescent light vanished as quickly as it appeared. The upper body of a hybrid Duelist that had just emerged from the shadows vaporized instantly.
"Attention, forward area. Servo-skull has detected significant traces of hostile biological activity," an operator reported concisely over the internal channel.
Before the voice even faded, a torrent of fire resembling a searing curtain of rain roared past! The blue electric snakes of arc rifles crackled through the narrow space, volkite weapons spat continuous streams of burning light, and phosphex weapons released lethal, sickly green flames... The swarm of hybrid Acolytes howling out of the darkness hit a wall of invisible force. They were torn apart in an instant, turning to ash or exploding into splashes of shredded meat and mud mixed with metal fragments.
"Enemy nodal organism eliminated," a sharpshooter's calm voice confirmed.
The faint light at the muzzle of his Exitus rifle faded. A hybrid leader in the distance, who had been attempting to organize a second wave of attack, now had a cauterized hole piercing through the center of his forehead. This type of precious weapon, which originally required the meticulous handcrafting of a Tech-Priest, had seen its STC templates restored under the mass-production efforts of Prometheus Labs. It had now become standard equipment for the Tempestus Scion sharpshooters.
This exquisite coordination was no accident. For an experienced Inquisitor, simply arming soldiers with better gear would be a waste of resources. Using her tactical insight, Sibylla had presided over a small-scale structural reform of the Tempestus Scions, forming unique combat units.
It was called the "Four-Three System."
Four men formed a squad: a heavy melee position, a fire support position, a sharpshooter position, and a drone/tech operator position. Three squads were organized into a group, led by a group leader responsible for tactical coordination, resource allocation, and liaison with higher command. A full-strength group totaled thirteen people—exactly the Emperor's holy number.
Now, this brand-new organization was demonstrating its terrifying adaptability.
Sibylla was not surprised by the efficient and cold advancement of the Tempestus Scions. Her attention was not entirely on the slaughter before her. Instead, like an invisible radar, she cautiously spread her Alpha-level psychic senses like tentacles, scanning the massive and twisted steel structures around them.
Sibylla was searching. She was searching for even filthier traces—the corruption of Chaos.
With her powerful psychic abilities, Sibylla was confident that any large-scale cult ritual or Warp contamination would struggle to escape her perception. In the depths of this hive, which was comparable in scale to a small continent, it was unrealistic to expect a single unit to kill every Genestealer. Maintaining the current overwhelming fire suppression to make these xenos understand that biting this hard bone would cost an unbearable price—forcing them to retreat temporarily—was enough.
The Inquisitor's primary objective remained the Chaos cult mentioned in the Eldar prophecy, lurking in the deeper shadows. Since the prophecy hinted that they were connected to Genestealer activity, perhaps even using it as cover, investigating along this line was the most direct strategy.
As she moved with the squad while sensing her surroundings, her foot kicked a hard object. Sibylla looked down and stopped in her tracks. She leaned over and picked up a weapon from a pile of wreckage mixed with purple blood and metal shavings.
It was a standard-issue hellgun.
The Inquisitor used her finger to wipe away the grime near the bolt, revealing a clear inscription—the Mark of Mars. This was standard equipment from Holy Mars, of superior quality.
As the battle progressed and they moved deeper, the enemies they encountered began to include more organized units—such as hybrid Neophytes. Those third and fourth-generation hybrids had hands more similar to humans and could operate human weaponry. Just moments ago, a small group of Genestealers had attempted to establish a blocking position using the ruins. Although their crude defenses were shredded in an instant by the fierce and precise fire of the Tempestus Scions, Sibylla's gaze became suspicious.
Genestealer Cults certainly scavenged and used human weapons, but they were typically battlefield trophies or crude civilian products. For a piece of standard military hardware in such perfect condition to appear in the hands of xenos elites at the very bottom of the hive...
Her thoughts connected instantly. A hypothesis surfaced in her mind.
Was someone—specifically an official power capable of mobilizing regular Imperial armaments—secretly supporting or even arming these xenos cults?
Who was it?