A buried UFO slowly turns local inhabitants into gizmo-building alien mutants.
In the small town Haven, in Maine, the aspiring writer Roberta 'Bobbi' Anderson lives in an isolated house with her alcoholic boyfriend, the poet James "Gard" Gardner; and their dog Petey. While Gard is traveling to a poet's convention, she stumbles with a green stone and she becomes obsessed to excavate the object. Further, she overhears voices that teach her how to fix the heater and how to write a novel using a typewriter operated by telepathy
As the people of Haven become more obsessed with their inventions, such as Nancy Voss's "disintegrator ray", Merrill goes missing and town's telephone line cuts off. Convinced that something in Haven caused his grandson's illness Ev Hillman begins researching the town's history, Trooper Butch Duggan returns to Haven looking for Merrill and his missing troopers and Anderson is determined to uncover the object.