This morbidly titled Czechoslovakian film was based on The White Diamond, a play by Karel Capek. Set in a mythical country, the story concerns a dedicated doctor (Hugo Haas) who discovers a cure for a dread disease that has decimated a goodly portion of the populace. The doctor refuses to reveal the secret of his miracle serum unless the country's despotic dictator promises to cease his warlike behavior and press for peace. Alas, the dictator refuses to listen, the country goes to war, and the doctor and his cure are lost to the Ages. Obviously designed as an allegorical statement against Fascism, Skeleton on Horseback was filmed in 1937, just before the German takeover of Czechoslovakia. Realizing that the film was tantamount to his own death warrant, star/director Hugo Haas fled to the United States, where his career continued unabated (albeit on a less lofty level).