An ice axe, a bloody study in Mexico City, and a betrayal years in the making.

In this episode, we uncover the true story behind the brutal assassination of Leon Trotsky. At its centre is Ramón Mercader, a Soviet-trained agent who infiltrated Trotsky’s inner circle and killed him. But this was more than a simple murder - it was the result of Stalin’s ruthless drive to eliminate all rivals and consolidate power.

With us is Josh Ireland, author of "The Death of Trotsky: The True Story of the Plot to Kill Stalin's Greatest Enemy". He explains the shadowy politics of Stalin's Kremlin, and how manipulation and conviction put Mercader on a path to Mexico City...