Actress Helena Bonham Carter (The Crown, Harry Potter series) explores the stories of both sets of her grandparents—neither of whom were conventional war heroes, but who both saved countless lives during World War II. She learns how her grandmother used her position to speak out against anti-Semitism, and discovers her grandfather’s role as a Spanish diplomat in helping Jews escape the Holocaust.

Actress Carey Mulligan (Mudbound, The Great Gatsby) travels to Japan to find out more about her grandfather’s experiences as a British naval officer during World War II. Speaking with historians and others impacted by the war, she discovers how her grandfather survived a Kamikaze attack, and learns the extent of the devastation he witnessed in Tokyo.

Actor Kit Harington, who has played soldiers, spies, and – in Game of Thrones – warriors, discovers that his grandparents played comparable roles in their real lives during WWII. Speaking with family members and historians, he gains a new appreciation of the courage and sacrifice all four grandparents shared as they fought for their country and for a cause.

Actress Keira Knightley (Pride and Prejudice, Atonement) has starred in several films set during World War II, yet admits she never knew much about her grandparents’ actual wartime experiences. Now, through conversations with family members and historians, she learns of the triumphs and tragedies her grandparents faced during some of the biggest conflicts of the century.