Adam Crenshaw is tired of living in his little sister's shadow. She wins everything, and he gets the leftovers. Big brothers are supposed to be the role models, right?
Then one day, all that changes. Louie is a leprechaun who offers him all the luck he could possibly want - for a price. The offer is tempting, but Adam refuses to work with him. To teach him a lesson, Louie steals all of his luck, and Adam's life is turned upside down.
Adam now has a choice between giving in to the leprechaun's demands, or losing everything that matters to him.