Six months after the death of Andy's mother, his father remains emotionally distant and largely ignores his twelve-year-old son. Andy channels his sorrow and anger into delinquent behavior in order to get attention. He needs a father figure, and finds one in Mr. D, a mysterious ex-con who moves in next door. Mr. D's reclusive habits and Hell's Angel appearance spark distrust among the townspeople, who suspect he's behind a string of local crimes. But Andy discovers that Mr. D is well educated after his years in the slammer, where he was mentored by a former scientist. Desperate to recapture his father's attention and love, Andy sets his sights on winning a science competition and with Mr. D, sets out on a seemingly impossible mission: To build one of Leonardo da Vinci's flying machine designs, something which has never been done before. Their unlikely friendship deepens as Andy and Mr. D struggle to overcome the project's technical problems and the town's prejudice, and Andy develops a sense of curiosity about the world and confidence in himself. In the film's final scenes, the flying machine's near-disastrous flight serves as a catalyst to bring Andy and his father together again while simultaneously freeing Mr. D from his self-imposed social exile.