Three famous guests — Stephen King, Gloria Reuben and Courtney B. Vance — know almost nothing about their fathers’ histories.

Billie Jean King, Derek Jeter and Rebecca Lobo learn about their family histories. King discovers that her grandmother was an orphan; Derek Jeter investigates his ancestors' lives as slaves; and Lobo finds out that an ancestor was forced to flee Spain because of his democratic ideals.

Ken Burns learns that his Southern ancestors include Confederate soldiers and a slave owner; Anderson Cooper learns that an ancestor on his father's side was killed by one of his slaves; and Anna Deavere Smith learns about her great-grandfather, who was a free black man and former conductor on the Underground Railroad.

Actor Ben Affleck discovers his mother's past as a Freedom Rider in 1964, NAACP President Ben Jealous learns how far his great-grandfather would go to keep his family whole, and actress Khandi Alexander learns about her grandfather's death.

This episode is not available from pbs because actor Ben Affleck had persuaded Gates to omit information about his slave-owning ancestors. In the investigation, PBS said that producers violated network standards by letting Mr. Affleck have “improper influence” and “by failing to inform PBS or WNET of Mr. Affleck’s efforts to affect program content.”

Chef Tom Colicchio learns the hardships his family endured in Northern Italy; chef Ming Tsai traces his roots back 2,000 years; chef Aarón Sánchez learns his Mexican roots include Spaniards, Africans and Native Americans.

Nas learns about his slave ancestors; Angela Bassett discovers that her family history includes an emancipation story; and Valerie Jarrett, a senior adviser to President Obama, learns about the free people of color in her family's past

Tony Kushner learns how the Holocaust impacted his ancestors; Carole King delves into the origins of her family name; and Alan Dershowitz discovers that an Hassidic synagogue started by his great-grandfather played a secret role in World War II.

Tina Fey, George Stephanopoulos and David Sedaris, three quintessential voices in American life, descend from ancestors that were part of the wave of Greek immigrants that flooded America’s shores in the early decades of the 20th century.

Secrets encoded in their genomes challenge these guests’ ideas about their families’ histories and their identities today. This episode features Jessica Alba, Anderson Cooper, Valerie Jarrett, Governor Deval Patrick and more.