Doctor Who episode 595: Terminus – Part Four (23/2/1983)
‘This is Terminus: no-one’s happy here.’ I think this is easily the best episode of the story because the themes of freedom and self determination suddenly come into focus as the Garm, the Vanir and finally Nyssa assert their independence, and hope conquers despair. Whether that’s enough pay off to probably the most joyless Doctor Who so far is debateable, but it at least feels like the slog had some purpose.