Evan had started with plenty of guesses: a massive, planet-sized beast lay below, and this was its mouth or nose.
A Necron tomb lay below, which would explain the bizarre technology.
An Aeldari base lay below, which would likewise explain the mystical forces.
But now, it really seemed to be some peculiar natural phenomenon. Crystal shards struck Evan's power pack at tremendous speed, making him feel as though he were facing Drukhari Splinter Weapons. Some of the fastest crystals even reached bolt-round velocities. His shield intercepted them, but its energy reserves were dropping.
Before long, the storm briefly subsided, and Evan and the warriors took the two mortals and immediately raced downward.
Their window of safety was short. The crystals blown upward would soon fall back down, bringing another shower of shards.
Leaping and weaving, the group descended at tremendous speed. The two mortals were suffering badly now. Only Astartes physiques could withstand such violent exertion. The acceleration from their constant changes of direction tore at their bodies, while the difference between internal and external air pressure caused by their rapid descent nearly made them vomit all over Evan's face.
Before long, the rapid descent reached the limits of human endurance. Evan stopped. The two mortals could go no farther; the speed of their descent had even left them struggling to breathe.
"Chapter Master, are we going farther down?"
"Keep exploring. I need to take these two back up."
The warriors split into two groups. A small contingent covered Evan as he climbed upward, and the falling crystal shards put them through another round of punishment.
This experience also hardened Evan's resolve completely.
I'm gonna build a super-waaaaaagh mech and cram all three of us inside. Then I can go cruising around battlefields just like the Chief Librarian.
*Wait, couldn't