On the surface, Sonia and Graham Starr were an unspeakably glamorous couple: she, the sleek and intense entrepreneur; he, the boyishly handsome painter with an irrepressible joie de vivre. But when their four-year-old daughter, Roxie, disappears into the Pacific Ocean, their world crumbles around them. Months later, twenty-one-year-old Colleen, who was the nanny for the Starr family, plagued by guilt and confusion, returns to the beach house where she once worked. On her first night back, she sees a child who bears a striking resemblance to Roxie, but when she calls out, the child runs away. The loss of Roxie has changed everything. Graham and Sonia have since split up. But to Colleen, it never made sense that Roxie, who was afraid of the ocean, would run into the waves on her own. Now that Colleen has seen either Roxie or her doppelganger, she is determined to get to the truth, even if it means facing her own complicity.