About to be electrocuted for a catalog of heinous crimes, the unrepentant Horace Pinker transforms into a terrifying energy source. Only young athlete Jonathan Parker, with an uncanny connection to him through bizarre dreams, can fight the powerful demon.

Professor Daidōji has developed a gravity machine called the GX Device. Unfortunately, Shocker wants it; so they attack the professor and destroy his laboratory, but come home empty-handed. Shocker's agents find out that the plans for the GX Device are with Daidōji's daughter, who is celebrating her birthday. Now the Kamen Riders, along with FBI agent Kazuya Taki, must protect Daidōji's daughter and prevent Shocker from obtaining the plans.

When Erin's special effects whiz father gives she and her friend Marty the first tickets to a new theme park ride, they think they have won the jackpot. However, when the ride breaks down midway through, things quickly go from bad to worse.