Set against the political backdrop of the Moscow Show Trials and the exile of Leon Trotsky in Mexico, a Spanish agent of Joseph Stalin's notorious secret spy ring, the GPU, is sent to assassinate Trotsky. After killing the exiled Bolshevik, Ramon Mercader has spent 20 years in a Mexican prison. The Prophet of Sorrow is a tale of suspense, courage, and love as recounted by the assassin. The main characters are involved in the tumultuous civil war in Spain, recruited as Soviet spies, trained in Russia, and unleashed as part of Stalin's private army of gangsters and murderers. Ramon Mercader and his mother are in a relationship rooted in a reign of terror led by the masterful old-time spy Leonid Eitingon. The famous artist David Alfaro Siqueiros masterminds an armed assault on the Trotsky compound in Mexico, but fails. It is up to Mercader to murder Trotsky through deceit and delivering the fatal blow with a mountain climbing axe, which was hidden under his coat.