A year after the events that killed her sister and turned her into a siren, Vanessa is desperately trying to put her family back together and reclaim a 'normal' life. But no matter how many times she swims, or how much salt water she drinks, she can feel herself getting weaker and weaker. Meanwhile she's desperately trying to come to terms with her break-up with Simon. Her first love, who she drove away with her siren's wandering eye.
Then her biological mother shows up at her summer house in Maine - claiming she is a Nenuphar, the most powerful of all sirens. She promises that she wants to help the daughter from whom she's been separated for far too long. But can Vanessa trust her? Now Vanessa must face the harshest . . .