Stanley Grubb (Josh Gad), the world's most boring and dull man, has a shadow named Stan (Kevin McDonald) who wants more excitement but can't have it because he's attached to Stanley. When Stan uncovers a criminal plot in the shadow world that involves an evil shadow who wants to lead a rebellion to take over the human world, he decides to take control of Stanley to give him a glimpse of adventure and to also stop the shadow villain from leading the rebellion. The two of them goes onto an adventure throughout the shadow world to investigate the situation and face the villain before the villain and the shadows set out to the human world to take control of their humans. Stanley has a love interest named Heidi (Kate Hudson).