Fawlty Towers was an iconic yet short-lived British comedy series created and starring John Cleese of Monty Python fame. The show was about the antics of the impolite manager of a hotel in Torquay. Due to the show being short lived, ending after 12 episodes, there have been persistent rumours of the existence of a thirteenth, lost episode. The most prominent of which being ‘The Robbers’, which originated from the fanbook titled Fawlty Towers: A Worshipper’s Companion by Lars Holger Holm, who dedicates a whole chapter to tell the story of how an ex-BBC employee let Holm see a lost thirteenth episode at his flat in 1999. After viewing the episode, Lars ran the entire script through a copy facility on a fax machine and features the script in his book. According to Holm, The episode was supposedly going to air on January 6, 1980 but was never aired.
However, John Cleese confirms that the existence of a thirteenth episode is total nonsense and this is backed up by official BBC book, Fawlty Towers Fully Booked.