Rocky Morton and Annabel Jankel direct this family adventure based on the Super Mario Bros. characters. When Mario (Bob Hoskins) and Luigi (John Leguizamo), plumbers from New York, are called in to help out with a flood at a dinosaur excavation site by the beautiful Daisy (Samantha Mathis), they become embroiled in a struggle with a parallel reptilian universe, ruled by Koopa (Dennis Hopper), a leader who wants to merge it with Earth.