GROTESQUE

Film special effects artist Orville Kruger brings his daughter, Lisa, and her friend, Kathy, to the family's remote country house in the San Bernardino Mountains. En route, Lisa and Kathy are harassed by a gang of punks driving a Volkswagen van, led by Scratch, who is planning to rob the Krugers' home. Scratch and his group are on the run after committing a robbery and mass murder of a family in Nevada.

Lisa and Kathy arrive at the house, where Lisa's mother informs them that Lisa's uncle Rod, a plastic surgeon, is arriving the next day. In conversation, Lisa has a conversation with her mother about how "Patrick" is doing, and Orville later plays a prank on the girls using his special effects creations. That night, Lisa and Kathy are awoken by Scratch and his gang, who hold the family hostage and threaten them, demanding they give the gang their valuables. When Orville states they have none, the gang bludgeons him to death with a log before killing Lisa's mother. From behind a glass slot in a wall, a pair of eyes look on as the gang brutalize the Krugers.

The gang begins a rape attempt against Kathy before a female member of the criminals stabs her to death. Lisa manages to escape the house and flees on foot. The gang proceeds to ransack the house before departing, and finds a hidden room decorated like a nursery. A hideously deformed man—revealed to be Lisa's adopted brother, Patrick, murders two of the gang members before the rest flee into the woods. Scratch and his girlfriend, Shelley, decide they will fight Patrick. At dawn, Lisa is attacked by one of the gangsters, but Patrick arrives and saves her, killing him.

Rod arrives at the house and finds police there, who suspect the missing Lisa may have committed the murders. Lisa is later found unconscious in the woods by authorities. Meanwhile, Scratch and Shelley come face to face with Patrick, who attempts to kill them, but he is subsequently shot dead by police. Lisa, suffering a blood clot, is hospitalized, while Scratch and Shelley falsely claim to have been innocent victims of Patrick. Lisa subsequently dies during an emergency operation; with the only witness to the crime now dead, Scratch and Shelley are due to be released by police.

Rod tells authorities that the deformed and deranged Patrick was abandoned as a child and raised by the Krugers, who kept him contained to ensure he would not hurt anyone. Upon realizing that Scratch and Shelley are to be freed, he rents two surgical tables and procures a shotgun. Outside the jail, Rod kidnaps the two and drives them back to the Krugers' country home. In a makeshift operating room, Rod reveals that he too is deformed, removing a mask made by his brother Orville to conceal his facial deformity. Rod surgically mutilates Scratch and Shelley before locking them inside Patrick's soundproof nursery.

The events are subsequently shown not to be real, but a test screening of a feature film hosted by the Frankenstein Monster and the Wolfman. The Frankenstein Monster and the Wolfman burst into the screening room, frightening the audience.

The film concludes with the gang's plot violently unraveling as the family's hidden mutant exacts brutal revenge, culminating in a freeze frame ending.

This ending flips the tables on the home invasion trope, making the invaders victims of the very secrets they sought to exploit. The freeze frame final shot underlines the film’s campy, self-aware tone, leaving viewers with a wink to its B-movie roots and the unpredictable nature of horror.