After her father murders her mother, Elle Carroway moves into the foster care system with her younger sister. Sinking deep into depression, Elle’s only relief comes from reading books under the trees outside. But when an intriguing boy named Eryk Rylander appears in her backyard, Elle discovers a new way of looking at her problems. According to Eryk, mental illness is caused by parasites called Charmers. Eryk offers to show Elle how to become a Mystic-a creature with enchanting powers that can remove parasitic Charmers. With her depression worsening daily, will Elle be able to leave her baby sister alone in the foster care system, to become a Mystic and get her Charmer removed?