The last priest of Acheron, a former Imperium fighter pilot on the run, and a defective warp witch are abandoned to their fates on a planet soon to be incinerated by a sun going supernova.

Together, they engineer an escape both from the Death Cult of the Skull God and from the dying planet, and they combine and pit their meager might against the merciless Emperor God, who destroys all peoples and planets that dare stand against him.