The Avengers (partially found TV series; 1961)
The Avengers is a British spy-fi series that first aired from 1961 to 1969. The show is known from evolving with its dynamic cast, starting as a crime show that became more sci-fi with time.
The detective duo in season one, Dr. David Keel (Ian Hendry) and John Steed (Patrick Macnee), were the show's initial protagonists. When Ian Hendry left the show, Steed's character became the main character. The show is often divided into eras based on the show's stars and co-stars, a trend that continued until the show's finale in 1969.
Like many British shows of its time, several episodes of The Avengers are now considered lost. The show was shot on 405-line videotape using a multicamera setup, and the tapes use for shootings were wiped and reused, a practice that led to the loss of episodes from Doctor Who. Only three episodes (Girl on a Trapeze, The Frighteners, and Tunnel of Fear) and part of the pilot (Hot Snow) of season one have been found as telerecordings. The rest of the series hasn't been found.