In olden times an alien craft crashed in the sea not far from Edinburgh. Its only surviving passenger burrowed into the ground and took up permanent residence. This deadly parasite from outer space controls all it surveys while the human population, its food, is unaware of the creature's existence. In modern times a small self-appointed team of ne'er-do-wells take on the impossible task of saving the world. Unknown to almost all of humanity this horror resides in subterranean darkness beneath a Scottish moor. Armed only with guts, wits and a peculiar device called the PXI the human heroes try to unravel a centuries old mystery. Is it possible for a mere human to penetrate the dark secrets of an alien being? Can man overcome the stupendous odds? Living on a diet of dissolved human flesh the alien creature blinds its victims to reality by using a mind-bending psycho-control. Inevitably there are people who are immune to the hypnotic influence of the alien—they have to be eliminated or at least neutralized.