originally due to be produced as the climax of season 20. However, due to an electricians' strike, the story was postponed and, with minor rewrites, resurrected for season 21. The story was originally supposed to have been directed by Peter Grimwade, whose work on Saward's previous story Earthshock had pleased the writer. When the story was postponed, Grimwade took members of the production team out to dinner, but did not invite John Nathan-Turner, because he had intended to take Nathan-Turner out separately. Nathan-Turner felt slighted by the omission and refused to allow Grimwade to direct the story when it was rescheduled for season 21. Matthew Robinson, who had never worked on the series before but had a "reputation as an action director", was used instead. However, Saward had already promised Grimwade that he could provide a script for the season, so Grimwade was allowed to write the following story, Planet of Fire. As well as the change of director, the serial's postponement also meant that Michael Wisher, who had originated the role of Davros in Genesis of the Daleks (1975), became unavailable. Matthew Robinson cast Terry Molloy instead and showed him the tape of Wisher's performance. The filming location for the serial was Shad Thames and Butler's Wharf in September 1983, with studio scenes videotaped at TC8 of BBC Television Centre between September and October. Story format This story was intended to be four parts of the usual 23-minute length. However, due to the BBC's coverage of the 1984 Winter Olympics held in Sarajevo, Yugoslavia, the series' regular slot was not available. Rather than interrupt transmission, the decision was taken to transmit the story as two double-length episodes (46 minutes per episode), on consecutive Wednesdays rather than season 21's normal Thursday/Friday timeslot. It is often asserted that it was directly because of the success of the two-part experiment that the following season was produced in the same format: however, this decision had already been made. The first copy of the story to be sold to American PBS stations by the BBC was done in the original four-part serial format. However, part two had a raw soundtrack, lacking sound effects and music. The compilation version, in which the entire story is compressed into one feature-length episode, had the entire second half with the raw soundtrack, but the second quarter with music and effects intact. The portions with the raw soundtrack also