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

In a first for the series, father-and-son comedy double-act Jack and Michael Whitehall join forces to investigate their family tree. They discover the tragedy that left Jack's great grandfather (Michael's grandfather) an orphan. And tracing their line back to Wales in the 1830s, they find out about a Tory ancestor's role in opposing the Chartist movement for wider voting rights.