'Harry Potter' star Daniel Radcliffe discovers that the Hatton Garden robbery of his great-grandfather’s jewellery business was far more dark and dramatic than he ever imagined, while an unseen cache of his great-great-uncle’s letters reveals a heart-wrenching First World War love story.

Actor Naomie Harris’s dramatic discoveries in this episode inspire her to anger, sadness and tears of joy. On a journey from Trinidad to Grenada to Jamaica, Naomie exposes her four-times-great grandfather’s involvement in the exploitation of so-called 'liberated Africans' shortly after the abolition of slavery, is delighted to discover the identify of her African five-times-great grandmother, and, in nearer generations, uncovers a family story of tragic poverty in Jamaica’s capital, Kingston.

In a first for the series, father-and-son comedy double-act Jack and Michael Whitehall join forces to investigate their family tree.

Canadian comedian Katherine Ryan’s investigation of her family history leads her to a Methodist minister and his family in colonial Nova Scotia, cod traders in Newfoundland, and eventually to her English roots in Dorset.

Paul Merton traces the life of his maternal grandfather and discovers that he was involved in some of the key events that led to Irish independence in the 1920s.

Sharon Osbourne uncovers the difficult circumstances of her mother’s and grandmother’s lives, and is stunned to learn that her great-grandmother was born in the US.

Former TOWIE star Mark Wright discovers that his ancestors included an Andalucian master swordsman and a Spaniard who was burned at the stake during the Inquisition.