Nine celebrities trace their family trees to explore the lives of their ancestors and uncover major themes in British social history. Irish actress Dervla Kirwan became a household name in the hit series Ballykissangel. But she has never spoken about her great-uncle Michael Collins, a national figure who changed Irish history and fought to establish the Irish Free State. Dervla wants to find out how her grandfather Finian, Michael's nephew, fits into the events shaped by his famous uncle. In the heart of Dublin, Dervla goes to Cathal Brugha Barracks to unearth Finian's pension records which detail his activities before he joined the Irish Free State Army. Dervla makes an unexpected discovery regarding the IRA, and uses the documents to help her retrace Finian's steps. She heads to Clonakilty in West Ireland where the War of Independence was at its height when Finian was still a teenager. Dervla knows little of her paternal side of the family and meets her father who tells her that her great-grandfather Henry Kahn was Jewish. Knowing nothing of the Dublin Jewish community, Dervla heads to the Jewish Museum. Armed with new information Dervla discovers a Victorian love story, a dismal miscarriage of justice and an act of anti-semitism that even reached the House of Commons - and inspired an episode in one of the greatest novels of the twentieth century, Ulysses by James Joyce.