In the formation's centre were the Captain and the Ancient, surveying the area in search of any signs they were close. The wind that whipped the high dunes did not reach the depths of the gulley where they marched. Instead, their path was clouded by a thick teal smog that rose from fractures in the ground beneath them. The gas was presumably from a toxic reservoir frozen over from millennia past, though it had no effect on the marines due to the rebreathers built into their helmet grilles. The sun could barely light their way, needing instead to rely on their helmet lights and enhanced ocular lenses. They kept note of each other's whereabouts by the rippling orange blush emitted by the energy outtakes of their armour's power-packs that lit the surroundings like rows of candles in a ministorum chapel. Waves of white soot were kicked up by the marine's approach. The snaps of soft ice lurked in the fog, too far away to derive any causes. The ring of adamantine idols and bolter barrels glided further onward into the unknown until the Sargeant of the spearhead reported a sighting back to the Captain. A familiar vox-buzz intersected Gerad's train of thought. 

"Titan coming up ahead Captain, Reiver-class chassis."

"Perfect, that matches our reports. Hold march until we find the others." Gerad exclaimed.

The fog thinned further forward of their position, providing guidance to the 7th as to where was safe to step. The Titan's gargantuan feet left craters from when it walked from which small ponds formed of prehistoric ice melted into a chunky arctic soup. Natural steps in the terrain were raised as a result of the god-machine shattering the terrain. Following its tracks, they had traced it back to its perpetrator. 

The colossal steel corpse of the reiver unit Vigilance Unending had sat rotting in sleet and rust for the past few hours. Its titanic skull was to the shape of a pair of binoculars, with two shattered glass domes that housed the units Moderati, who controlled its movements and weapons. It was in such a state of disarray no amount of prayers or Omnissian canticles could resurrect it. Wires the girth of trees were uncoupled from their chambers and leaked great pools of the machine's umbral blood. The titan's exterior was melted and putrid with chemical burns and clots of cold white slag dripping from its primitive wounds. It was clear that these were not the product of concentrated firepower, rather more disorganised slashes and cuts. The two Moderati were nowhere to be seen in person amongst the wreakage, however their mangled helmets had fallen from their perched cockpit. What shook Gerad the most was the sight of the titan's body. It looked as if it was cut in half, with industrial intestines splayed out in a tangled cluster of burnt plasteel. Burrows had been shaped into the titan's innards, tunnels not big enough to fit a normal man, let alone a space marine.

A flailing figure jaunted toward them, darting from under the half-severed finger of the machines power-fist. The front squads readied their aim in quick succession, instantly focussing on the target's centre mass. The thing in the mist cried out in a language resembling their own. A sharp order from Gerad made them creep closer toward their target, keeping their ears open. The Princeps had revealed themselves to his saviours, sending the Captain to a powerwalk toward him. The company quickly reformed their ring of steel around their catch. 

"Princeps Hephaestes, glad to see you alive." Caption Ixion loomed over him as his aegis, not wanting to let his focus slip at the princep's discovery.

"Oh, but by a hair Captain."

Hephaestes was a warrior of his own class incomparable to the Astartes. To be a princeps meant devoting your entire being to the Machine God over decades to reach a peak of worship the thralls of the Cult Mechanicus loathe and the Archmagi adore. One had to be willing to sacrifice any dreams they had in a future free of service to the Omnissiah. As the primary controller of a titan, the princeps must bend the machine spirit to their bidding by sheer force of will and mental fortitude. Without such a senior member, a machine of the god-engine's calibre would simply not function. One's ascension to such a position requires a deep understanding of technology and the machine god's mission. As audaciously taught by the Mechanicus, comprehension is the key to all things.

The Princeps was clad in flat carapace armour that shook off flakes of wrought paint with every movement. In the socket his left leg once was, a prosthetic that ended in a crude heavy foot was affixed to a smoothed stump halfway to the length of his thigh. The only human part of his appearance was his face. His shrivelled bald scalp had aged gothic tattoos etched onto it, the most prominent being a regal Aquilla that spanned across his browline. He had bionics grafted to his skull to enhance his vision with additions such as range-finders and infrared camera settings. He was hunched over with his service laspistol scrunched in his palm.

"Are any of your comrades alive Princeps? Any other titan crews?" Gerad interrogated him.

"None from the Vigilance Unending, either they fled into the snowfields or were eaten alive in their seats." Hephaestes struggled to recollect the encounter. 

"It had all happened so quick, a swarm of the Xenos tore us apart at the waist. Our tech-priest on board and most of the servitors were crushed inside when our top-half fell onto the ice. I evacuated the control throne in time to outrun whatever was clawing its way in. My Moderati..."

 He took notice of his crewmates' ravaged helmets.

"...were not so lucky."

The Captain shivered at his interpretation of the princeps' account. Eaten alive...? Gerad had never considered such an animalistic approach from the foe. He was accustomed to fighting soldiers, not beasts.

"Rest assured Princeps sir, no harm will come to you in-"

"Contact Left! Fire at will!"

Gerad was cut off by the scream of one of his sergeants, followed deafening clap of bolter fire. Two squads opened combined fire toward a group of grotesque silhouettes barreling into their formation. The gargling cry of the Xenos drew the attention of the Captain. He rushed behind the bulwark of his leading company men, joining in with a rapid hail of rounds from his pistol. Chunks of mass vanished from the wiry shadows, indicating back to them any successful hits. The creatures escaped their sight again, dividing themselves into smaller cells. 

"Form up men! Protect the Princeps!" Gerad shouted defiantly.

The battle brothers linked shoulders to form a barricade with their bodies, not letting even the winds pass through them. Every marine sat in rank with calculated determination, studying every anomaly in their vision. The alien wails ricocheted on every surface, unable to be traced to any one location. Gerad fell back to the centre of the formation to join Zalthen, who was zipping his head around in quiet confusion. The things revealed themselves again meters ahead of the defenders, giving them little time to react. Neanderthallic horrors leapt on scrawny clawed limbs into the frontline from multiple angles. They had adapted to the captain's tactics as soon as he employed them. The drilled marksmanship of the marines claimed a majority of the marauding force, flicking them out of the air with a single bolt round. Those who weaved a path through the marines defence vaulted onto them, screeching the whole way. Brothers were battered down by the alien's charge, puncturing gaps in their barricade. Gerad and Zalthen fired wherever they could, filling the hole in their defences from a distance. 

Though their ranks were thinned, a small few vagrants made their way in. Gerad freed his hand of his pistol and drew his power axe, decorated with ultramarine heraldry and the name MACRAGGE scribed on its cutting edge. He flicked over the activation run at its hilt, initiating the high pitch whir of the power generator. The axehead was roiled in galvanic brilliance as he sprinted to meet the invaders. He fought with angry grace, compensating for each strike by throwing his storm shield at his vulnerable areas. Every slash slid through the flesh of the Xenos, sending them into electric spasms as they fell until none remained. The last attacker Gerad slammed with his shield before splitting its grotesque jaw with an upward swing that left sizzling blood in its arc. Returning to his surroundings, he had noticed the others had killed off the rest of the attacking force. He froze in place, trying his hardest to control his adrenaline. His burgundy soaked hands trembled as he reached for his vox caster.

"Machellus, this is Captain Ixion. We've secured one of the princeps, all other personnel are unaccounted for. We make way for the southern fortress to extract who we have left. Address the Auxilia and send them to the fortresses airfield for reinforcements."

"As you wish sir." Machellus acknowledged.