In the story, the brilliant consulting detective Sherlock Holmes is asked to investigate the disappearance of a wealthy man named Neville St. Clair. A beggar called Hugh Boone, the story's title character, an extremely ugly and filthy looking man, is detained by the police on suspicion of having murdered Neville St. Clair. After Holmes spends a night contemplating the known facts of the case, he realizes that Hugh Boone is connected to Neville St. Clair's disappearance in a completely different way. There have been several adaptations of the story to other media.