Courteney Cox traces her maternal line back to ambitious and ruthless relatives who plotted and murdered their way to power in medieval times; and she's shocked to discover an ancestor who's one of European history's most famous characters

Julie Bowen makes a shocking discovery that a beloved relative lead a nefarious organization that triggered a dark chapter of U.S. history; and uncovers another ancestor who risked everything to fight for the lives and freedom of African Americans.

Jennifer Grey discovers much more about the grandfather she thought she knew as she uncovers how he survived adversity to become a beacon of his community; and discovers a great-grandmother whose devastating tragedy stopped her from making it to America.

Noah Wyle investigates his maternal family line, discovering an ancestor who was catapulted into one of America's biggest wars, and whose life spiraled out of control from remarkable success to a shocking and tragic end.

Jessica Biel hunts for the truth behind family lore surrounding the death of an ancestor. She also makes two shocking discoveries that shake everything she knows about her heritage to the core.

Motown legend and icon, Smokey Robinson tracks down a grandfather tangled in a swirl of controversy and connects to a relative's familiar struggle with oppression while coming face to face with the gruesome history he knew was inevitable.

Actor John Stamos explores his Greek heritage for the first time and discovers an explosive feud that shattered his grandfather's childhood. He also meets a relative he never knew and hears firsthand about his family's enduring strength.