on Blake's 7 for four years and as the BBC didn't want anyone working on two shows at the same time. Producer Graham Williams had worked with director George Spenton-Foster previously on Z-Cars and chose him to direct this serial due to his experience with night filming. Spenton-Foster would direct one more time for the series in the following year's The Ribos Operation. Script editor on the serial was Robert Holmes in his final assignment. During the work he was trailed by incoming editor Anthony Read, who would subsequently take up the role solely for the next story in production order Underworld (the following transmitted story The Sun Makers having been recorded before Image of the Fendahl). Read had been a television producer but was asked by head of Serials Graeme McDonald to be script editor to which Read refused until he learned it was for Doctor Who. McDonald had read through the scripts for Fendahl and objected to a scene in part four which showed Stael raise a gun to his mouth. This was changed at the order of producer Williams and the gunshot is only heard. Following this serial, the horror elements under Holmes' guidance were considerably toned down at the order of McDonald. The exterior scenes were shot on the Stargroves estate in Hampshire, which was owned by Mick Jagger. The same location had been used during the filming of Pyramids of Mars. Filming began on Monday 1 August 1977 and continued until the following Thursday. This included two night shoots for the serial on the Tuesday and Wednesday evenings. The first night's filming was disrupted when the generator caught fire. Another generator had to be ordered from London and arrived at 4am. Filming at the estate had only been agreed on the 26 July – less than a week before filming began, with the instruction (as had been the case with "Pyramids of Mars") that no effects or explosions were to be undertaken given that the property was a Grade II listed building. Two days after filming was completed Tom Baker and Louise Jameson attended the world's first ever Doctor Who convention in London. Following rehearsals, studio recording for the serial began on Saturday 20 August and was completed on 6 September 1977. Wanda Ventham, playing Thea, had previously appeared in The Faceless Ones, and would subsequently appear in Time and the Rani, her three appearances