Dr. Claw's mother (the one person in the world he fears) orders him to take care of his nephew Billy while he's on summer vacation from his boarding school. She also tells him that Billy is unaware of their family's criminal history and that's the way she wants it to stay. Far as Billy knows, he's being sent to stay with his Uncle Gordon, a wildlife biologist studying the animals on a tropical island. So that's what he tells Penny when he meets her at the airport when she arrives on the same island for a camping vacation with her uncle. Gadget's arrival infuriates Dr. Claw and gives him the problem of how to eliminate his enemy while keeping his nephew from knowing he was involved in Gadget's demise. Fortunately, his experiments on controlling the wild animals of the island offer a solution.