All that is certain about Sergei Prokofiev is that he was a musical genius and one of the greatest composers of the 20th Century. With the discovery of his personal diaries, the mystery that was Prokofiev is about to be revealed. Prokofiev fled Russia shortly after the Bolshevik Revolution. He spent the next eighteen years trying to build a successful career in North America and Europe. Then, he made a decision which stunned the world: he returned to Russia in 1936, at the height of the Stalinist purges. Now more than fifty years after his death, this documentary reveals the largely untold story about the pivotal eighteen years (1918-1936) outside Russia, the years which sealed his fate. Through the intimate, revealing and often heartbreaking words of Prokofiev's diaries, the film investigates Prokofiev's life and art through his own words and the prism of some of his most extraordinary musical creations.