From the morning of the 10th August 1979 to 5.38 pm on 24 October 1979, the ITV network was blacked out, and did not transmit any programmes at all, due to industrial action, with the ACTT union on strike. This is the reason why the final four episodes of the first series' second serial were transmitted months after the rest. (The first four episodes of the second serial were repeated in the run up to the first screening of episode five, to jog viewers memories.)