When a fragment of an ancient alien superweapon surfaces in the depths of hyperspace, its discovery sets off a race to find the extraterrestrial doomsday device. Hopping from planet to planet in both the civilized Pact Worlds and beyond, the heroes must contend with both the undead Corpse Fleet and the nihilistic Cult of the Devourer, each of which seeks to acquire the alien artifact for its own purposes.