 Several severe accidents happen in different amusement parks. Technical supervisor Calder suspects it s no coincidence and starts to investigate. Soon he finds out that a psychopath blackmails a whole conglomerate of companies for a million dollars, and urges them to inform the FBI. But the blackmailer, who observed the company bosses all the time, learns about it and demands that Calder delivers the money... and sends him on a nerve-shattering trip through an amusement park to deliver the money, while the FBI observes him closely and tries to bust the electronically skilled terrorist.