At Magic Mountain, Abner Devereaux, Anthony Zerbe the park's engineer and the creator of a string of animatronic attractions, watches his work compete for attention with Kiss’s high-profile concert plans. Park owner Calvin Richards, Carmine Caridi, explains that the concert will bring in crucial revenue to fix nagging quality-control problems that have plagued Devereaux’s creations. A park guest, Melissa, Deborah Ryan becomes uneasy when her boyfriend Sam Farrell, a park employee and Devereaux’s assistant, goes missing. Meanwhile, three troublemaking punks sabotage one of the rides, and Devereaux is quickly blamed for the mishap.
Melissa tracks down Devereaux and heads to his underground laboratory—the last place Sam was seen. Devereaux claims he hasn’t seen Sam, but after she leaves, it’s revealed that Sam is under mind control thanks to a neck-mounted device. The three saboteurs enter the Chamber of Thrills and fall into Devereaux’s traps, while Richards fires Devereaux for unstable behavior and a blatant disregard for guest safety. With his livelihood threatened, Devereaux vows revenge on Richards, the park, and Kiss.
Soon after Kiss plays its first concert at the park, Devereaux tries to ruin them by unleashing a robotic copy of the Demon, the stage persona of Gene Simmons. The authorities question the band, but no action is taken, and Richards, along with the police, ends up apologizing for the incident and exonerating Gene of sabotage. Melissa seeks help from the band to find Sam, unaware that the security pass she received from Devereaux actually contains a tracking device. Devereaux has Sam break into the band’s lair to steal their talismans, but their case’s force field foils the theft.
Kiss infiltrates the park to confront Devereaux, fighting off his robotic white monkeys as they maneuver through the tunnel-like corridors of the underground lab. Sam does manage to steal the talismans and hands them to Devereaux, who then neutralizes Kiss with a ray gun. The real Kiss is imprisoned while Devereaux broadcasts robotic copies to take the real group’s place on stage and incite a riot. The true band regroups, retrieves the talismans, and regains their powers just in time to confront the imposters and save the concert.
After the show, Kiss, Melissa, and Richards confront Devereaux in the underground laboratory, where he sits in a catatonic state, seemingly revealed as the park’s phantom. Paul Stanley removes the mind-control device from Sam, restoring him to normal. Richards laments Devereaux’s downfall with the line, He created Kiss to destroy Kiss...and he lost. An alternate take uses the final dialogue He created KISS...to defeat KISS...and in the end, it destroyed him.
> He created Kiss to destroy Kiss...and he lost.
