and Pedler left the series at the conclusion of the second series in 1971, the series turned into a more conventional thriller drama. The two creators openly criticised this change. The first two series each consisted of thirteen episodes, and the third of twelve, of which one, titled "Sex and Violence", was not transmitted. It has been suggested that this was because of objections to either its use of stock news footage of a public execution in Lagos, or its presentation of characters designed to be satirical analogues of Mary Whitehouse, Cliff Richard and Lord Longford. The execution footage has appeared on British television a number of times since 1972, notably in a 1988 edition of Panorama about violence on television. Doomwatch was popular, and at its peak drew audiences of as high as 13.6 million for the episode "Invasion", filmed mostly in the village of Grassington in North Yorkshire. The start of every series merited a cover feature on the BBC's Radio Times listings magazine, which even today is a prestigious feat for a programme. The series was also sold abroad, gaining some popularity when transmitted in Canada. Archive loss after production As was common at the time, the BBC wiped the Doomwatch master tapes soon after transmission, regarding them as being of little further use. Although some episodes have been returned from Canada or exist as telerecordings, many are still missing and will probably remain so, although all are being sought by the BBC Archive Treasure Hunt as a whole. However, a copy of the un-broadcast episode survives in the archives, one of only three from the final series to do so. Series two is complete, thanks to the returns from Canada, but series one is missing five episodes. All of the existing episodes, other than "Sex and Violence", were repeated on the satellite channel UK Gold during the 1990s, although that episode was erroneously published in broadcast schedules. Cast and crew The main character throughout the series was Nobel Prize winner, Dr Spencer Quist, who had been given the task of setting up and running the department by the British government. Quist is haunted by guilt through having worked on the Manhattan Project, making the first nuclear bomb. He was played throughout the BBC run by John Paul, a familiar face from a range of British television series, who later went on to appear in I, Claudius.