All seventeen-year-old Maggie Warshauer wants is to leave her stifled life in Filliyaw Creek behind and head to college. An outsider at school and uncertain of her own sexual identity, Maggie longs to start again somewhere new. Inspired by a long-dead biologist's journals, scientific-minded Maggie spends her days sailing, exploring, and categorizing life around her. But when her beautiful cousin Charisse disappears on prom night and is found dead at the marina where Maggie lives, Maggie's plans begin to unravel. A mysterious stranger begins stalking her and a local detective on the case leaves her struggling to hold on to her secrets—her father's alcoholism, her mother's abandonment, a boyfriend who may or may not exist, and her own actions on prom night. As the detective gets closer to finding the truth, and Maggie's stalker is closing in, she is forced to comes to terms with the one person who might hold the answers—herself.