Set in World War II, this comedy drama follows a troubled young boy called Peter (Dean Stockwell), whose hair mysteriously turns green after he receives some unfortunate news. After being sent to live with various unsympathetic relatives and finally being placed in the care of the kindhearted Gramp Fry (Pat O'Brien), Peter finds out that his parents have died in the London Blitz. That night, Peter's hair turns a vibrant green colour, which leads to him being bullied by children and adults alike. Peter then runs away to a forest where he meets fellow orphans who tell him he has to pass on an important message to the townspeople. But will anyone listen and will Peter's hair be green forever?