DON'T GO IN THE HOUSE

Donny Kohler is a withdrawn man in his thirties who is obsessed with fire—his fixation stems back to his childhood, during which his sadistic, abusive mother would burn him on their gas stove to "burn the evil out of him." After returning from his factory job one evening to the dilapidating Victorian home he shares with his now-elderly mother, Donny finds that she has died in her upstairs bedroom. This spurs mixed emotions—initially of excitement, as he is finally freed from her—but alternately, fear, as he begins to hear a disembodied voice in the house that seems hers.

The following day, Donny calls in sick to work and spends the day lining an upstairs room with aluminum, effectively fireproofing it. That night, he visits a flower shop right before closing and is sold flowers for his mother by a florist named Kathy Jordan. Outside the shop, Donny sees Kathy miss her bus before she is harangued by a group of men. When Donny offers her a ride, she accepts. Donny talks Kathy into meeting his mother, but she grows nervous once inside and attempts to call for a taxi before Donny incapacitates her.

Kathy regains consciousness and finds herself naked and chained to the ceiling of the metal-walled room. Donny enters the room in a fire suit, douses Kathy in gasoline, and burns her alive using a flamethrower. The following day, Donny fails to show up to work and instead kidnaps a stranded female motorist, again murdering her by immolation. He then proceeds to singe his mother's corpse before dressing it in her clothing. Donny repeats the same murder scenario that night with Linda, a woman he assails at a grocery store, and arranges her alongside his mother and the other two female victims.

Donny's friend Bobby phones him that night and warns him that their boss will fire Donny if he fails to show up to work again. Meanwhile, Donny is haunted by apparitions of his burnt mother, who appears to stalk him inside the house. Donny spends hours regaling the four corpses with stories from his life, which he has arranged and posed in chairs in a bedroom. Riddled with guilt over what he has done, Donny visits Father Gerritty, his local priest, to discuss the nature of evil. Donny confesses to Father Gerritty that his mother repeatedly burned him to rid him of his innate "evil."

Later, Donny accepts his friend Bobby's invitation to go on a double date at a disco. When Donny's date tries to pull him onto the dance floor, she inadvertently brushes his arm over the table's lighted candle, triggering memories of his childhood abuse. Enraged, Donny smashes the candleholder onto her head, setting her hair on fire. Donny flees the disco and, en route home, encounters two drunk women whom he convinces to come home with him. Bobby tries to find Donny and stops by Father Gerritty's on his way to Donny's house. When no one answers the front door, they break it down and rescue the two women. Donny sets Father Gerritty ablaze with his flamethrower, but Bobby manages to extinguish the flames and rescue him. Donny takes refuge inside his mother's bedroom. The voices express their disappointment in him, and the burned corpses come to life and attack him. He frantically fights them but dies; they drag him to the floor as the house burns down around him.

Sometime later, a young boy named Michael watches the news report about Donny's death. His mother scolds and beats him for not turning off the TV as she asks him to go upstairs and clean his room. When she leaves the room, Michael hears the same voices as Donny, and they tell him they have come to 'help' him.

Donny is ultimately confronted in his house after a series of murders; during the rescue of his intended victims, he attacks with his flamethrower but is stopped.

The climax resolves Donny’s reign of terror as his actions finally draw the attention of those around him, leading to intervention and the prevention of further tragedy. The ending underlines the destructive cycle born of unresolved trauma, suggesting that Donny’s attempt to exorcise his own demons only perpetuates horror. His downfall is framed as both a personal and social reckoning—one that leaves scars long after the flames die down.