Pioneering 18th-century barrister, William Garrow, revisits the Old Bailey to champion the rights of prisoners against the power of the State, as BBC One's acclaimed drama Garrow's Law returns for a second series. When 133 African prisoners are thrown overboard from slave ship The Zong in suspicious circumstances, Garrow challenges the brutal trade that regards slaves as cargo, not human beings. Widowed and alone in London, Garrow's friend and mentor, Southouse, grapples with his inner demons. However, Garrow's return proves timely as Southouse's life spirals rapidly into introspection and despair, making him focus on the future and his legal career.Southouse is approached by an insurance company that wishes to prosecute The Zong's Captain Collingwood, who is accused of inventing his story in order to conceal a massacre and claim compensation.