The book opens with a recounting of the story of a case in 1853 in which two men, Cartwright and Firman, enter into a deadly argument. Cartwright is chased by vigilantes but he kills off one of the mob before they capture and hang him. It's noted that the identities of the mob were generally known, but that the men weren't punished for the lynching. This remains the "most sensational" event of the area of Plainfield, Wisconsin, until a century later when a man named Ed Gein will "make the name of Plainfield, Wisconsin, forever synonymous with darkness, insanity, and unimaginable horror." Ed's father, George, is orphaned at the age of three. George marries Augusta, a strictly religious woman who concedes to having intercourse only for the sake of parenting. They have two sons, Henry and Ed. The family moves to a farm near Plainfield while the boys are young. When George dies, the boys and Augusta work the farm. Henry dies mysteriously in a wildfire though the death isn't questioned until years later. When Augusta dies, Ed is left alone and lonely.

Ed soon stops working on the farm and lives in squalor in the house without electricity or indoor plumbing. Ed is not exactly shunned though he has few friends. He does hire out regularly as a handyman, painter and as part of farming crews during harvest season. He is always willing to help his neighbors and often runs errands or even babysits. He enjoys the company of young people, seemingly uncomfortable around adults. It's this friendship with a young boy, Bob Hill, that apparently prompts Ed to show off one of his prized trophies - a pair of preserved heads that he says were sent to him by a relative from the South Seas. When another boy reports seeing three of the heads on Ed's bedroom door, the rumors begin to circulate that Ed's house is haunted though the children who fear the house don't seem to fear Ed himself.

Meanwhile, Ed is descending into full-blown madness. He spends the majority of his time with cadavers retrieved from area graveyards. He cuts off skin, preserving faces so that they resemble masks. He strips skin and uses it for covering chair bottoms. He preserves lips, noses and genitalia. He also commits a murder, killing a tavern keeper named Mary Hogue because of her evil ways. The murder occurs in broad daylight but Ed's role is not discovered for some three years, until the death of another business woman, Bernice Worden. Bernice is the owner of a hardware store and Ed shoots her in broad daylight as well. This time the victim's son immediately names Ed as a suspect and Ed is quickly arrested. When police enter his home, they find Bernice's headless corpse hanging in the summer kitchen, having been dressed like a deer. The officers then discover Mary's face, skin and an array of other body parts throughout the rooms Ed used.

As the case unfolds, Ed admits to robbing graves but refuses to admit to murder, insisting that his shooting of Bernice must have been accidental and that he doesn't remember the details that came after. The media descends on the little community throughout the investigation, exhumation of two graves, and the decision that Ed is insane. A full trial ten years later finds Ed guilty and he is ordered to return to the mental hospital. A petition for release is later denied and Ed dies in the facility, leaving behind a legacy of ghoulish details that have influenced pop culture for the decades since the discovery of Ed Gein's death house in 1950.