‘I think your Doctor’s worse than mine.’ This plays more like a comeback for Jamie than the second Doctor. Frazer Hines fits right into the line-up, with an easygoing rapport with Baker that suggests, given the right companion, the sixth Doctor would be a much more attractive proposition. The difference is his disagreements with the Doctor are banter rather than snide asides, and taken in good spirit, whereas half the lines Peri gets are acidic put downs or complaining that would make Tegan look mellow by comparison. The Baker-Bryant-Hines trio make this quite fun, even when a lot of the content is grim verging on inappropriate.

Holmes is a good enough writer that even lackadaisical direction can’t entirely rob this of a sense of forward motion (even if the second gas trap in a fortnight suggests no-one on the production team was really thinking about this hard enough). The sixth Doctor’s investigations on Space Station Camera go on far too long given the idea of a conspiracy to set up the Time Lords doesn’t really go anywhere, but at least it’s better than having him sit out half the episode in the TARDIS or locked in a storeroom which are the alternatives offered this season. And when he briefly believes the universe is about to end, he gets a nice Holmes monologue about eternal blackness only slightly undermined, now, by memories of The Fast Show’s Johnny Nice character. Meanwhile, Troughton gets to handle all the Dastari and Sontaran exposition scenes while lying on his back – nice work if you can get it.

Dastari, it turns out, is another of Holmes’ insane scientists, like Greel and Davros (depending on how much of Genesis of the Daleks Holmes was responsible for). Like Davros, he waxes lyrical about the gods – although he’s more interested in setting Chessene up among them than he is himself. Like Greel, he’s searching for the secret of stable time travel for his time cabinet – a secret that lies in the flesh. The problem is, he’s one of four main villains competing for oxygen, and even though Laurence Payne plays him quite well he’s the most colourless of the lot. Strangely, given it’s supposed to be her genius behind everything, Chessene’s almost equally bland – were she not played by Jacqueline Pearce she’d be entirely forgettable. At this stage, you have to believe that Pearce is being held in reserve for the finale because the material she’s given here – such as chatting to Peri about the number of bedrooms in the villa – is, perhaps deliberately, bathetic.

Stike the Sontaran doesn’t get anything much more interesting – but I’m fascinated how his mask and gravelly voice makes him weirdly like a Valentine Dyall Spitting Image puppet. Apparently, Holmes consented to add the Sontarans to the shopping list because he felt subsequent writers hadn’t done them justice. Here, he has the second Doctor needle Stike about honour and courage, suggesting that in Holmes’ view they’re the Klingons of the Doctor Who universe. It’s a pity that they’re the weakest of the show’s attempts to give monsters of the 1970s a 1980s makeover because I think Holmes was right: Stike is the best-written Sontaran since Jingo Linx.

The last and most memorable of the baddies is Shockeye, a grotesque creation who eats Doña Arana and a rat, raids the villa’s kitchen and assesses Earth’s culture on the standard of its cuisine. While Dastari is obsessed with Chessene, and Stike with warfare, Shockeye’s own monomania is an insatiable appetite for the flesh of Jamie and Peri. In a rare cliffhanger that doesn’t focus on Colin Baker’s face, this episode ends with him pursuing Peri through the baked countryside, dressed in his odd motley like Leatherface in The Texas Chain Saw Massacre. The final image of him reaching directly to camera for her – for us – is the most striking in the entire episode.

Next episode: The Two Doctors – Part Three