Henry Louis Gates, Jr. and his team use both DNA testing and detective work to uncover the history of a grandparent line for comedian Andy Samberg, whose mother wants to know who her parents who gave her for adoption as a baby were, and Game of Thrones author George R. R. Martin, who wants to know more about his grandfather who left his grandmother to start a new family. Both guests learn about deep family secrets they had no idea about which causes both joy and frustration for them.