Philip Dodd discusses the enduring fascination with the Marxist revolutionary Che Guevara, the subject of a new biography and a film. He looks at Simon Reid-Henry's Fidel and Che, which explores the friendship between the rebel Fidel Castro and the itinerant doctor Che Guevara, as well as Soderbergh's films Che: Part One and Part Two, which tell his life story and feature Benicio del Toro in the title role.