Derek Thompson, a minor-league ice hockey player known for knocking out his opponents' teeth, does not believe in fairy tales or magic. One day, after crushing a young fan's hopes by telling him that the tooth fairy isn't real, Derek magically receives a summons under his pillow. This summons is a warning for his actions, leading him to a mysterious realm where he is sentenced by a fairy court. His punishment: to serve as a tooth fairy for two weeks. Armed with a set of wings and some magical gadgets, Derek embarks on his new nightly duties with a mix of confusion and clumsiness. Through his journey, he encounters several obstacles and challenges that test his beliefs and character.

As Derek adjusts to his unexpected role, he begins to understand the importance of dreams and the power of believing in something greater than oneself. His gritty, no-nonsense approach to tooth fairy duties initially causes mayhem and misunderstandings in the magical world and among the children he visits. However, these experiences also open Derek's eyes to the impacts his real-world cynicism has on those around him, particularly on his relationship with his girlfriend Carly and her two children, who start to see a different side to him. Through his misadventures as a tooth fairy, Derek learns valuable lessons about life, love, and the importance of keeping the magic of childhood alive.