An orbital infantry squad descends into a collapsed dome on Helikon-3 to secure a buried research annex and extract its data. Inside, combat units hunt through the tunnels, using human bodies inside exoskeletons that adapt and keep fighting.

The deeper they move, the clearer it becomes the annex is still active, reshaping what it finds into something operational. Comms degrade, structures fail, and the system begins reacting faster than they can predict, turning every corridor into a controlled environment.

What begins as a recovery mission shifts when control over the systems is lost...

This is "Annex Theta 9" by Sascha Schmidt