The Orcus Convergence

From publisher blurb: The subterranean caverns on the world of Thar Darul are the scene of odd occurrences that a group of aggrieved miners ask the PCs to investigate. What they discover is an unexpected and deadly attempt to infiltrate the planet and subjugate its people. Worse, the mine manager has no idea what is occurring in his mine — and the miners want to keep it that way, even if it means the adventurers’ untimely end.