Season 24, Episode 4 | 3 parts | First broadcast: 23 November – […]
Season 23, Episode 4 | 2 parts | First broadcast: 29 November – […]
Season 22, Episode 4 | 3 parts | First broadcast: 16 February – […]
Season 21, Episode 4 | 2 parts (double-length) | First broadcast: 8–15 February […]
Season 20, Episode 4 | 4 parts | First broadcast: 15–23 February 1983 […]
Season 19, Episode 4 | 4 parts | First broadcast: 15–23 February 1982 […]
Season 17, Episode 4 | 4 parts | First broadcast: 24 November – […]
Season 16, Episode 4 | 4 parts | First broadcast: 25 November – […]
Season 15, Episode 4 | 4 parts | First broadcast: 26 November – […]
Season 14, Episode 4 | 4 parts | First broadcast: 1–22 January 1977 […]