A young man named Francis is relaying a story to an elderly man of the recent ordeal he and his fiancée Jane have undergone, Jane's affections for which he and his friend Alan had once competed. That ordeal involves two unsolved murders and an attempted abduction. While the police initially suspect a man who is indeed a criminal as the murderer in these two instances, Francis believes the murderer is a Dr. Caligari, and his pawn, a sleepwalker named Cesare. Francis and Alan first spotted Dr. Caligari and Cesare as a carnival sideshow act. Francis' belief is that Dr. Caligari is using an unwitting Cesare to to commit these acts of murder. As Francis nears the conclusion of his story, details contained within are shown not to be as their appear on the surface.—Huggo