Mr Sideney was a student wizard who needed to earn a lot of money quickly to pay off his debts to Chrysoprase the Troll during the events of Hogfather. Foolishly he decided to join Mr Teatime's scheme to inhume the Hogfather. His part in it was to open the magically sealed locks at the top of the tower in the Tower of Teeth. Having done so he fled, and then found that he has returned to his infant school, was five years old again, and was at the mercy of the school bully. In the movie version, he sucked his thumb so naturally met his end at the hands, or scissors, of the Scissorsman. The Scissorsman is a reference to the childhood bogeyman who comes to children who suck their thumbs in the story, "the Scissorsman" (Struwwelpeter) by Heinrich Hoffmann.