‘Bring them all out, all the nasty human beings. The Caretakers, the Residents, the Kangs, all of them.’ I think it’s mostly Briers as Kroagnon that really irks fans. The Chief Caretaker was a heightened version of his Ever Decreasing Circles character, in keeping with the other inhabitants of the Towers. But Kroagnon is just a joke performance that’s only occasionally funny (the look he gives Pex when they’re hurrying through the corridors). A more interesting choice might have been to tone it right down, so that Kroagnon and the Doctor suddenly become the only characters in this world with any gravitas, worthy opponents. Instead, it equals Graham Crowden’s death scene in The Horns of Nimon without the excuse that Briers didn’t know it was a take rather than a run-through. Fittingly, for such a rubbish villain, he gets a rubbish death scene – pushed through a door and exploding, rather than anything more creative.

The real climax is the lead-up to that moment, where the Doctor manages the impossible, uniting the various factions in the Towers to join forces not only to destroy their common enemy but to continue that détente even after Kroagnon is dead. Scenes of elderly Rezzies hijacking the cleaning robots with home-made tablecloths is very funny, especially the juxtaposition of that with the very impressive explosions. Pex’s final sacrifice adds some poignancy, and the last image of the story – ‘Pex lives’ under united red and blue scarves – is the first of the McCoy years’ many neat little epilogues.

Made a series later when this version of the show has found its feet, Paradise Towers might have gone down as one of the classics. Even here, though, it’s palpably superior to anything since The Caves of Androzani. It fizzes with creativity and a sense that Doctor Who should be fun. I’d almost forgotten what it’s like when the script editor actually likes the character of the Doctor and celebrates him – ‘The Doctor really is ice hot’ – in a way that’s almost New Series. Mel is delighted to be reunited with him, and they hug. There are obviously bad bits (like the deadly Pool Robot attacking Mel in the shallows about a foot from the edge), but I think overall the show is getting it right again.

Next episode: Delta and the Bannermen