After the violent death of her father, in which she is complicit, sixteen-year-old Margo Crane takes to the Stark River in her boat in search of her vanished mother. But the river, Margo's childhood paradise, is a dangerous place for a young woman travelling alone, and she must be strong to survive, using her knowledge of the natural world and her ability to look unsparingly into the hearts of those around her. Her river odyssey through rural Michigan becomes a defining journey, one that leads her beyond self-preservation and into deciding what price she is willing to pay for her choices.