"Three dead. No one injured." Sergeant Rhadvek reported as I reloaded my autogun. Once I realized my aides were alive and most of the men were present, I set my mind to moving forward. Either way, they were going to make it into the xenos-chambers along with us. Now we knew where they were, in a manner of speaking. 

"Form them up. V-Columns" I told the sergeant. A dependable man, with a sharp face and a hard way about him. Most of the troops I had been given were green or PDF, but the sergeant was certainly an exception. He called for the men and set them to formation, four of them made of a dozen men each. Each wing had six men, maximizing the area of fire and minimizing casualties if fired from the left, right, or forward. Emmaline and Lazarus stuck close to my person, though much to Emmaline's distress I strode ahead with my men flanking me, stepping off the barren rock and entering the cavernous chambers of the inner sanctum. 

My first step into the 'lobby' as one might call it was a shock to my senses. Not in the physical realm, but my psychic presence felt wholly strange. It was as if my entire life I had been walking in rain, and now I stepped into a dry cavern, where stilled air and an enclosed environment altered all sensations of my form. It was not painful, but off-putting. As I walked past the first pillar, I felt the physical sensations rest on my face. The stale, stuffy air, frozen and encased for untold millennia. Breathable, and with surprisingly little dust for how ancient it undoubtedly was. 

There was a strange, gloomy ambient light that permeated all space, and yet somehow there was an overwhelming darkness behind every corner, every crevasse, every unknowable turn. As we moved, the foundations of the vast halls stuck out like large, insectoid feet. Green tendrils within the xenos-steel pulsated just as it did at the gate. Some universal and undeniably powerful power source. Lazarus gazed at our surroundings like I would read an old tome from the dark age of technology. 

"Find it fascinating?" I asked him, mostly to lighten the mood. The men were on edge. Like it or not, they were now within a xenos construct on a dead world chasing chaos cultists. Half the PDF were shivering.  

"Entirely..." The techpriest marveled. 

"Stay focused." I cautioned him. 

The halls were like fissures between tall cliffs, almost immeasurable in scope. The paths, however, were at least walkable. It was perhaps forty strides between the left and the right. We passed the first corridor and were met with a fork. Emmaline advised we go left, and so we did. As we progressed, the halls became more complex, with smaller chambers locked behind doors in the shape of caskets. One man cried aloud when he spotted a floating drone, much like those the xenos known as the tau used, I suspected. An abominable intelligence, though it didn't seem aggressive at its current state.