‘Mystical mumbo jumbo.’ What a shame this wasn’t broadcast as produced – the first story of the 20th series. I love its mixture of weary cynicism and a sense of wonder. It’s the best material Davison has been presented with, by a writer who, I sense, has seen what he can do and channels it into a Doctor every bit as compelling (and perhaps moreso) as the previous four. The Doctor is full of energy, dashing between the TARDIS, Ambril’s office and the marketplace like a madman. Which is, incidentally, what he looks like as he bursts into Ambril’s celebratory dinner with Tanha and associated lackeys. A lot is made of this Doctor’s determination in The Caves of Androzani, as if it’s something unique to that story. It’s not – he’s every bit as driven to save Tegan here as he will be Peri.

The Doctor’s energy contrasts with Tegan’s stillness. As he dashes about, so she lures Lon to her. Again, it’s as if Bailey saw what she did with Kinda, particularly the scene of her dropping apples on Aris’s head, and builds on it. Her seduction of Lon – he clearly thinks she’s just one of presumably many courtesans until she seizes him, her cruel mockery of the showman, and her genuinely unsettling encounter with Nyssa in the marketplace give Fielding her best material so far too.

The script is remarkable, nimbly reminding us of the stakes, when Ambril talks of the cultural catastrophe that befell the Manussans last time the Mara rose, and cleverly playing with audience expectations. I’m sure there were a few viewers who remembered the climax of Kinda and guessed the Hall of Mirrors was going to be the solution. Bailey subverts that, making it the location of the Mara’s rebirth. Characterisation is great, too. Tanha’s, ‘Shall we eat?’ and stifled yawn as Ambril lectures her; Ambril’s outrage when he realises that he is the sixth face of delusion; Chela’s belief in the Doctor when everyone else dismisses him as a lunatic. Even secondary characters like the showman are given dialogue that paints a whole lifetime beyond what’s onscreen:

I’m not a curious man. I was once, a long time ago. I was a humble student of life’s mysteries. A treader of the secret pathways, a delver into the darker corners and so forth. All rubbish, of course. At the end of the day, when the lights come up, as in one form or another they always do, there’s always somebody standing there with their hand out, waiting to be paid. I decided long ago that person might as well be me.

Next episode: Snakedance – Part Three