Once again, this isn’t exactly the most satisfactory conclusion. The Doctor talks about Greel’s vampirism as ‘a postponement of the inevitable’, and that could sum up this episode, which would have ended very differently had Greel been slightly more ruthless towards Leela at Litefoot’s house, or if he’d talked less and acted more at the House of the Dragon. Instead, there’s lots of frantic running about, wrestling, and explosions that mask the fact that Holmes, once again, hasn’t thought of anything more elegant.

Still, everything that transpires feels true to the characters Holmes has established. Leela’s courage means she takes it on herself to trail the Doctor to the House of the Dragon, where she’s instrumental in the showdown. And Mr Sin, who’s an insane pig creature, finally gives in to his lunacy and turns on his master. The reveal that Greel is ‘a foe from the future’ is neatly done, too. The implication is that he’s an unpleasant footnote in the new dark age of the 51st Century, a sort of Mengele figure whose perverted science was notable only for its cruelty and horror rather than its practical success. He’s not a Chinese god, or a renegade Time Lord, he’s just a vile human being who rightly comes out of this looking smaller and more pathetic than early episodes suggested. The Doctor’s mockery, his inability to follow through on his grand designs, his begging Leela for his life all make him look ultimately powerless. Like the worst Baker era villains, he has no sense of humour either: ‘I’ve never appreciated frivolity.’ And he’s a bad loser, when the Doctor beats him at chess.

I like the idea that this story is built around a series of deceptions and conjuring tricks, from Greel’s performance as Weng-Chiang, Mr Sin’s ventriloquist doll disguise, and Chang’s stage act, to Jago’s fake bravado, and the Doctor leaning into the role of the Great Detective. The Time Cabinet is another magic box that merely pretends to do what the TARDIS actually can. Only Litefoot is what he seems to be. In context, ‘Good trick, eh? I venture the great Li H’sen Chang himself would have appreciated that’ is the perfect sign-off for the story, and for the Hinchliffe and Holmes years as a whole: a great act that they got away with.

The Talons of Weng-Chiang is their best trick of all. Having worked their way through many of the old horror masterpieces – Frankenstein, The Mummy, The Wolf-Man, The Quatermass Xperiment, The Masque of the Red Death – it’s like they got to the end of an era and chucked everything that they hadn’t done into the pot. This has got The Phantom of the Opera, Fu Manchu, Jack the Ripper, Dracula, and a Dead of Night ventriloquist doll.

It’s also got Robert Holmes’ most unrestrained dialogue and elegant characterisation. He’s often praised for his double acts, and you can pick out loads here – Jago and Casey, Jago and Litefoot, Greel and Sin. But I think the “Holmesian double act” is a bit of a red herring. I think he’s just supremely talented at writing dialogue. Pretty much all the characters in this form mini double acts whenever they’re together. The Doctor and Litefoot, the Doctor and Jago, Leela and Litefoot – they have the gorgeous scene over Mrs Hudson’s cold collation, the Doctor and Greel. Holmes is brilliant at repartee, and that’s what makes his scripts sing.

This is obviously brilliant. It has a verve even beyond The Robots of Death, and immediately becomes the new high water mark of the series to date. But it’s not repeatable. Obviously there are elements that even a few years later would be unthinkable. The most regrettable thing about this story is the treatment of the Chinese. The ‘yellowface’ is bad, and is the product of the same TV culture that was churning out The Two Ronnies, The Black and White Minstrel Show, It Ain’t Half Hot Mum and numerous other examples of white actors playing ethnic minority roles – as they did in Doctor Who throughout the 1960s and 70s. This isn’t meant as a defence, more that to pick out The Talons of Weng-Chiang for special criticism is absurd.

The casual racism (‘inscrutable Chinks’) and making every Chinese a criminal (although the TV Movie did the same in 1996) is harder to explain. If you made something like this now, you might have Litefoot replaced by a Chinese detective on the trail of Greel, all the Chinese characters would be played by Chinese actors, and the Doctor would clearly disapprove of any racist comments. Plus the massive amount of knife violence would be completely unthinkable in any family TV made today.

This relies on some very specific circumstances: Holmes inspired by Robert Banks Stewart’s Foe from the Future storyline; Hinchcliffe’s willingness to blow the budget on his final story, and David Maloney being assigned to direct (imagine if he’d got Robots and Pennant Roberts had been allocated this). For better and for worse, this is a one off.

Next episode: Horror of Fang Rock