Doctor Who was having a party in 1983, and everyone was invited. While the main anniversary event of the landmark Season 20 was The Five Doctors, there was a celebratory air to the whole series, with old friends reunited and ancient enemies returning.
Producer John Nathan-Turner famously boasted that this season featured “an element from the show’s past in every single story”. Perhaps that claim only really worked if you sort of squinted at the Black Guardian trilogy in the middle, but the laps of honour for Omega and the Brigadier did feel suitably momentous, while rematches with more recent menaces – such as the Mara – added to the festive flavour. And all this before we even got to the TARDIS cocktail soirée.