When Susanna Kepner meets Lucy Yates at their university campus in a small city in Oregon, she feels as though there is something familiar about her that she just can't put her finger on. She also meets Lucy's mother, Jillian, whose intense reaction to meeting Susanna sets off alarm bells with its intensity. As she gets to know Lucy, she learns of her sister Kendra Yates who has been missing for almost two decades. The name stirs the same sense of familiarity in Susanna that Lucy does, and she resolves to find out more.After an online search, Susanna finds a picture of the missing girl and realizes that she's a dead ringer for Susanna as a child.Jillian is convinced that Susanna is her daughter Kendra and resolves to get her back, turning the lives of the Kepner and Yates families upside down.Is Susanna who she thinks she is, or has she been living a lie her entire life?