For years, Mallory McKenna has kept the secret to her family's vast fortune: an embittered leprechaun-nothing like the cheery fellows depicted on cereal boxes-who was captured by her forebears in Ireland. While most rich teens would enjoy the benefits of ancestral wealth, Mallory would rather not have to take care of a snarky magical creature who hates her, especially since she can't share anything about magic with anyone. Even if she could, who would believe her in a world where magic is mere myth? But when a clandestine organization kidnaps her parents in search of mystical secrets, Mallory's lavish life collapses, leaving her alone and desperate. In exchange for the promise of his freedom, the leprechaun agrees to help with a rescue mission. As they work to discover who is targeting her family, Mallory begins to understand the horrific plight of the mythical creatures that share her world, including the jaded leprechaun she's resented most of her life. But as the enemy closes in, Mallory realizes she'll have to make an impossible choice: turn her back on an endangered magical world in order to save herself, or do what is right, and lose everything.