The arrest of Augusto Pinochet in London in October 1998 was a landmark moment. It was the first time that a former head of state has been arrested on charges of genocide and crimes against humanity while travelling abroad. Five decades after the Nuremberg trial, the Pinochet case was the moment in which the idea of international criminal justice came alive once more. The central narrative of Pinochet in London is that untold story - the circumstances of his arrest, for crimes committed after he came to power on 11 September 1973; the extraordinary and tumultuous legal proceedings in London, with consequences in Madrid and Santiago; and his return. Relatedly, it's a tale about legal principles invented in 1945 and first invoked in Nuremberg's Courtroom 600 - the end of immunity - and personal stories and in Chile, Spain and Britain, a victim, a lawyer, a prosecutor, a friend, a judge.