‘The Doctor has journeyed dangerously to honour us here in Castrovalva, and look at the outcome.’ Though the Doctor is still in a weakened state, Davison’s cleverly inching his performance closer to “normal” every episode. The scene where he asks Mergrave to draw him a square to prove the impossibility of Castrovalva is great: he plays it with the slightly fusty authority of a professor, but with a streak of youthful impatience, recalling Hartnell’s young/old take on the part.

In minutes, he’s torn down the foundations of Castrovalvan society, its geography and its history. He then goes on to confront the Master with the very eagerness to sacrifice himself for his companions that’s finally going to catch up with him: ‘All right, Master. It’s me you want. Let the boy go.’ By the time he’s got his ‘ship-shape team’ to jog back to the TARDIS, where he adds a flourish of celery to his lapel, he’s much more promising than the diminished character of the early episodes.

And as the Doctor grows in strength and confidence, the Master seems to fall apart, losing all sense of proportion and self-control as he desperately tries to break into the zero cabinet (delivered to him via a symbolical funeral procession): Nyssa has to explain the cabinet can’t be opened from the outside, earning a shove and a ‘Don’t try to make a fool of me’. Oddly, he’s desperate for ‘one long last look’ at the Doctor: ‘I will see your face before I destroy you forever.’ There’s a subtext to this that’s much more explicit in the 21st Century series. By the time he’s reduced to screaming, ‘My web, my weaeaeaeaeaeb!’ we can only conclude he’s gone completely doolally. His Suddenly Last Summer exit, the predator torn to pieces by his prey, is a fittingly gothic demise (at least for now).

I like Castrovalva, while also thinking it’s very first draft. I don’t think anyone actually script edited it, and the story has a vague, out of focus quality that’s luckily in keeping with the tentative, unfinished regeneration. There’s a strangely sexist element to it which, given the Castrovalvans are all his fictions, might be supposed to imply the Master’s own disdain for the Doctor’s female companions (‘By a woman!’, ‘Why are all these women here, is it a holiday?’). I’m not entirely convinced the production has really got to grips with the script either. It’s another pinkish-grey story.

Next episode: Four to Doomsday