Karen Walker is an ex-homicide detective slowly recovering from the trauma of an automobile accident in which she was injured and her husband was killed when a drunk driver struck the car she was operating. After a year of surgeries and attempts to come to terms with her feelings of guilt, she finds herself living the narrow life of a semi-recluse.
Her seclusion comes to an end when an old friend from college, Clarissa Hammett, asks Karen to help in the search for her missing sister, Justine. Karen agrees, and she goes to live alone in the family’s summer home on the coast of southern Maine, which Justine was occupying at the time of her disappearance. Karen even goes one step further and takes on Justine’s job as hostess in a local restaurant, hoping to learn more about the missing woman’s life from her co-workers.
Conversations with the sister’s estranged husband, her present boyfriend, and a mentally disturbed young girl on the beach, lead Karen to believe that Justine’s disappearance was not voluntary and that, if still alive, she may desperately need help.