The serial is the only one of the original series to have been produced at BBC studios outside London. Engineering work at those studios meant that it was made at the Pebble Mill Studios of BBC Birmingham instead. According to the DVD commentary supplied by Louise Jameson, John Abbott and Terrance Dicks, a scene in part three was crucial to the behind-the-scenes relationship between Jameson and co-star Tom Baker. In one scene, he consistently came in ahead of his cue, thereby upstaging her. On the grounds that this move was "not what they had rehearsed" she insisted on three successive retakes until he came in at the rehearsed time. This eventually won his respect. From that point forward, she claims their working relationship was much smoother.