When Carole Hanson and her father travel to Minnesota to visit relatives, Carole has the perfect assignment to create a family tree. Ever since her mother died, Carole has been curious about that side of the family, especially about an ancestor who journeyed north along the Underground Railroad. Then Carole discovers a secret lurking in her family tree, and she begins to question where she's come from. Do bloodlines matter as much with people as they do with horses? Carole discovers the answer when a dangerous horseback ride threatens the life of one of her relatives.