Battle broke out in the fault zone at the edge of District Three.
Given the target's high threat level and the possible presence of powerful psychic units, Cassius held nothing back this time.
The residents of District Three fled the combat zone in terror after receiving evacuation orders.
The Sons of Medusa squad, meanwhile, revealed the terrifying resources they possessed as Clan Magara's elite.
The first thing to arrive was the roar of steel.
Three suits of Cataphractii Terminator Armour strode out of the Thunderhawk Gunship like mobile ancient fortresses.
Instead of the usual Assault Cannons or Whirlwind Missiles, they carried the classic combination of Storm Shield and Thunder Hammer.
Energy fields hummed across the immensely thick, curved shields, capable of blocking almost any incoming frontal fire.
The massive hammers in their hands, which required a two-handed grip and had heads wreathed in leaping lightning, were symbols of close-combat destruction.
Additional shield-generator modules were clearly visible on their pauldrons, making them seem shrouded in multiple energy shields as they charged.
Close behind came three Indomitus-pattern Terminators, equipped with twin-linked Assault Cannons or heavy flamers and exuding an air of destruction.
The Whirlwind Missile launchers mounted on their pauldrons would provide continuous, ferocious fire support for the Cataphractii ahead.
But that was not all.
With an even deeper roar of engines, a massive Redeemer-pattern Land Raider, heavily armored and brutal in its contours, rolled out of the transport.
The muzzles of its signature twin-linked Flamestorm Cannons were dark and deep, as though brewing the fires of hell.
These weapons could convert vast quantities of promethium fuel into torrents of flame that swept away everything, making them the ultimate tools for clearing enclosed spaces and densely packed biological targets.
The Space Wolves called it the "Flamewyrm."
Cassius himself had also donned Cataphractii Terminator Armour this time.
He stood at the very front of the squad, his white helmet like a beacon in the dim light of the fault zone.
The Iron Halo behind him slightly distorted the light.
In his hands was a larger, heavier, master-crafted Thunder Hammer, the arcs leaping across its head an ominous deep blue.
Under his command, this tide of steel slammed straight into the depths of the fault zone without flourish.
Fierce fighting erupted in an instant.
The Genestealer bishop's lair had far tighter and more cunning defenses than Lynn had imagined.
Large numbers of fourth-generation Genestealer Hybrids, some even approaching purestrains in physique, poured out from every direction.
Equipped with crude but effective weapons, they attacked using the complex terrain and preset traps.
Some mutants even seemed briefly enhanced by psychic power, their movements swift and their carapaces hardened.
But the Sons of Medusa's offensive was even more brutal and effective.
Led by Cassius, the Cataphractii Terminator squad advanced steadily like an unshakable wall of divine punishment.
Every blow of a Thunder Hammer came with the dull crunch of shattering bones, the sharp crack of bursting carapaces, and a dazzling eruption of lightning.
The Storm Shields steadily blocked bone blades, acid, and even low-powered energy shots.
The Indomitus Terminators' firepower was like a hammer, smashing apart any swarms that tried to flank them or gather.
Bolter rounds and flames scoured every corner of the caverns.
The Land Raider held a key passage entrance, its Flamestorm Cannons occasionally letting out a low roar.
What they spewed was not flame, but an almost liquid torrent of thick, burning promethium.
It instantly turned broad stretches into an incandescent sea of fire, with even the rocks melting in the heat.
Yet the presence of the Genestealer "bishop" introduced a variable into the battle.
Just as the Sons of Medusa squad was about to breach the outer defenses and close in on the heart of the lair, a powerful, deeply unsettling psychic fluctuation abruptly gathered.
Then a visible, distorted blast of pale purple psychic energy thundered out from deep within the lair like an invisible giant hammer!
It did not attack the flesh directly, but targeted the mind and soul, carrying intense sensations of fear, confusion, and tearing.
The accompanying Psyker who had distinguished himself in the previous fight against the Neurothrope, an old man whose eyes were tightly shut and who relied on mechanical life support, immediately stepped forward.
He raised his withered hands, attempting to construct a psychic barrier to block it.
"Ugh...!"
The two psychic forces collided violently!
The old man's entire body convulsed, and blood instantly seeped from all seven of his facial orifices. The warrior guarding him from behind even heard faint, teeth-grating sounds of rupturing from inside his body.
The barrier barely stopped the attack, and it had clearly done so by the narrowest margin.
There was even a faint scorched smell from the Psyker's internal organs burning under the psychic backlash.
"Suppress it!" Cassius's icy voice came over the comms, utterly level.
No further orders were needed.
The shoulder-mounted weapon of one Indomitus Terminator quickly switched modes, no longer firing bolter rounds.
Instead, it fired specially made Mindstrike Missiles, exceptionally effective against psychic creatures.
At the same time, the Land Raider's Flamestorm Cannons adjusted their angle.
A slightly narrower but hotter jet of promethium, like red-hot molten iron, poured precisely into the general area from which the psychic blast had come.
A shrill, inhuman scream rang out from deep within the lair, and the gathered psychic fluctuations instantly fell into disarray and dissipated.
The Genestealer bishop's first-and last-full-strength psychic counterattack had been defeated in the most "efficient" manner.
The price was that the accompanying Psyker had almost entirely lost his combat effectiveness, his internal organs severely injured.
And all of this had been witnessed by an "invisible" observer.
Atop a nearly vertical steel structure, no more than a few hundred meters in a straight line from the heart of the battlefield.
An enormous, hideous beast with a purplish-red carapace and folded membranous wings clung tightly there like the most patient gecko.
[Shapeshifter Armor] gave her the ability to evade the Sons of Medusa's sight.
Electromagnetic camouflage made her appear as background noise on the Auspex.
Her body temperature matched the cold rock face exactly, and she moved without a sound, even her vibrations absorbed by the damping mucus beneath her carapace.
Her pheromones were so faint as to be almost nonexistent, blending perfectly with the dust, gunsmoke, and scent of Tyranid bodily fluids permeating the fault zone.
Like a ghost from the abyss, Rena quietly "watched" the collision of steel and flesh below.
Cold streams of data flickered constantly in her compound eyes, recording every detail.
The rhythm of the Cataphractii Terminators' charges, the force and reach of the Thunder Hammers' attacks, and the Storm Shields' blocking of energy attacks.
The speed at which the Indomitus Terminators switched their firepower, and the range and coverage patterns of the Land Raider's Flamestorm Cannons.
The deep blue arcs leaping across Cassius's special Thunder Hammer.
More importantly, she "saw" the grievous injury suffered by that Psyker.
All this information was transmitted through the system in real time to a distant corner of District Seven.
To Lynn, who was pretending to conduct a "home visit" while investigating leads on the Cultists.
Lynn wiped nonexistent beads of sweat from his forehead, inwardly ranting:
Has Cassius really sold his ass to those Tech-priests?
Where did he get all this good stuff! Cataphractii Terminators, Indomitus Terminators, a Land Raider...
This loadout is enough to fight a small campaign!
But when he received Rena's report that the Psyker accompanying the Sons of Medusa had been grievously wounded.
A mixture of relief and resolve welled up within him.
A Psyker was a crucial component in dealing with unconventional threats, especially psychic attacks and certain Warp phenomena.
His severe injuries meant that, when Cassius's squad faced the next sudden psychic blast or interference.
There would be a brief but very real "weak point" in their defensive capabilities.
Now he only needed to guide Cassius's squad into clearing out the lair hiding that "heavy Tyranid weapon."
Then he could begin carrying out his plan.
Lynn looked out the window at the Hive City's perpetually dim skyline, where the low echoes of distant explosions could still faintly be heard.
"Senior Cassius," he murmured, his gaze sharp as a blade.
The stage is set, and the actors are all in position.
All that remains is to wait for the perfect moment to raise the final curtain.