Freewheeling, motorcycle-riding musician Johnny rolls into a small town with his band, and meets Kathy, an honor student who catches his eye. Meanwhile, Kathy's father, after being in the Witness Protection Program, is finally tracked down by two corrupt cops he escaped from years ago, who want the money he owes them.

John Brown is a bumbling but well-intentioned security guard who is badly injured in an explosion planned by an evil mastermind. He is taken to a laboratory, where Brenda, a leading robotics surgeon, replaces his damaged limbs with state-of-the-art gadgets and tools. Named "Inspector Gadget" by the press, John — along with his niece, Penny, and her trusty dog, Brain — uses his new powers to discover who was behind the explosion.