In Bolton, Massachusetts, three years after the Second World War, the private Herbert E. Dike starts to write his memories. During his writing, he starts to remember the sinister and strange events that happened to him during the conflict in Europe. He starts to remember how after a German ambush in Calais, in the north of France, he found himself semi-unconscious in the battlefield when the Sergeant of his unit, Ronald Meehan, woke him. Both privates start a search of the territory trying to find their unit, but they get lost in a strange land that doesn´t appear in the detailed maps of the area.
The two soldiers undertake the march walking miles until some buildings lost in the middle of a path into the dark forest. Soon they found a strange village that didn´t appear in the maps. When they entered the village, they found that a strange religious cult was doing human sacrifices and obscene rites praying to a horrible deity called Subb Niggurath. The horror that the private watched at that time is something that he never will forget. The weird events that he lived at that time bring him to absolute madness.