Grace Davis of Dubuque, Iowa is a studious bookworm that prefers companionship with fictional characters from fantasy novels over actual friends. When she is assigned to tutor two of her classmates at the local library, they discover an old house on the other side that has a long-abandoned treehouse. Their curiosity piqued, they enter the treehouse to discover that an etched inscription is actually an incantation - a rift to the world of Caliphee. Grace Davis is the prophesied Chosen One and must learn to harness the Four Elements to defeat the loathsome Tarrasque beast that has left so much death and destruction in its wake.