Willy (Matthew Knight) has a unique concern regarding his family's new house: he firmly believes it's inhabited by malevolent space aliens. Luckily for Willy, his wish for a savior is fulfilled with the entrance of Gooby (voiced by Robbie Coltrane), a strange but loveable creature who appears more anxious of the world's dangers than he is. As the unlikely pair become friends, Gooby helps Willy and his father reunite.