Her mothers third marriage is only hours old when all hope for Clares fifteenth summer fades. Before she knows it, Clare is whisked away to some ancient cottage on a tiny marsh island on Cape Cod to spend the summer with her father—a man she hasnt seen since she was three. Clares biological father barely talks, and when he does, he obsesses about endangered turtles. The first teenager Clare meets on the Cape confirms that her father is known as the town crazy person. But theres something undeniably magical about the marsh and the island—a connection to Clares past that runs deeper than memory. Even her fathers beloved turtles hold unexpected surprises. As Clares father begins to reveal more about himself and his own struggle, Clares summer becomes less of an exile and more of a return.