"The Mephisto Waltz" is a 1971 horror film directed by Paul Wendkos. The story revolves around a successful pianist, Eliot, who becomes entangled in a dark and supernatural plot involving a deceased composer. As Eliot learns more about the composer’s life, he discovers a sinister connection that threatens his own existence. The film is based on a novel by Gordon R. Dickson and features a blend of psychological horror and supernatural elements. It explores themes of ambition, possession, and the consequences of making deals with dark forces, ultimately leading to a chilling climax.