On an unnamed night-side planet, a recon platoon tracks a seismic engine moving beneath a glass-like fractured crust.

Inside its structure, the engine broadcasts a lattice pattern showing human colonies already marked for eradication.

The crust breaks open under the platoon, dropping soldiers into shifting machinery that moves like a living tunnel system. Thin corrosive air, unstable ground, collapsing ridgelines, and failing comms turn the tracking mission into a fight to keep moving.

This is "The Colony Eradicator" by Sascha Schmidt