 They have survived an earthquake and are now having to defend their only true home from pirates using their magic and the help of their teachers.As the book begins and progresses, Tris hears voices on the wind telling her seemingly useless bits of information.In an effort to cool herself off in the summer's cruel heat, she and her three "mates"—Sandry, Daja, and Briar—head up to the wall that encloses Winding Circle.