After Sharon McCone's father dies of a sudden heart attack, she immediately heads to San Diego to scatter his ashes and clear out his house. In a box of legal papers, she finds a 1959 petition for adoption of a child called Baby Girl Smith - an infant who, from the day of adoption, has been known as Sharon Elizabeth McCone.

No one in Sharon's family will discuss the adoption, so she begins her own search for the truth. Her quest takes her deep into Indian country, to the Flathead Reservation in Montana. When her birth mother is critically injured in a hit-and-run accident, Sharon begins to understand that her search has caused a resurgence of old hatreds and fueled present-day violence.