‘I’m not waiting around while you plot the course to your own destruction.’ Later, when the show offered this kind of thing every week for a couple of years, it became quite easy to be sniffy about the military SF of Earthshock, with ‘gritty’ working class soldiers (you can tell because one of them has a northern accent), macho posturing (Scott grabbing the Doctor roughly by his lapels) and a massive, gruesome body count. Here, it’s like a slap across the face. The series hasn’t offered up anything that’s tried to be this tough since The Seeds of Doom. It’s got a relentless pace, machine gunning you with scene after scene of people being reduced to goo in the dark.

While it’s not my favourite type of Doctor Who, it’s not unenjoyable, and it gives Season 19 something earthy after the vivid sophistication of Kinda, the airiness of Four to Doomsday and the wet gentility of Black Orchid. It’s better than The Visitation, keeping the idea of killer robots lurking in the dark, but actually making some effort to get us invested in their victims. Saward sets up a pretty compelling mystery – what has happened to Professor Kyle’s colleagues? – and clear peril, then drops the TARDIS into the middle of it.

He also writes the TARDIS crew better than in The Visitation. They’re still deeply dysfunctional (Adric is a needy teenager whining about the Doctor not spending enough time with him and demanding to go home), antagonistic towards each other in a way no previous team of regulars had been (the closest I can think is either very early Hartnell, or very early Pertwee). But as soon as the Doctor abandons Adric to his maths and goes exploring with Tegan and Nyssa it’s a different story. He gets to play the learned teacher – talking about the dinosaurs and their mysterious destruction; Tegan and Nyssa bounce off each other rather well. There’s a glimpse of a workable crew here. He’d already got the gig, but this feels a lot like Saward’s bid for the script editor position.

It’s also made really well. I like that women have been cast as leading soldiers: it’s a very basic touch, but it’s not always been the norm for the show. The lighting is great – for once, the caves look properly gloomy. The props are convincingly battered – not because they’ve been cheaply thrown together, but because some thought’s gone into realising the script’s suggestion that the military rely on clapped-out equipment. The dissolved soldiers are legitimately horrible. The androids are simply realised, but look effective as they flit through the shadows. Only the cliffhanger left me doubtful: so, the androids are being controlled by different androids? The end credits at least confirm that one of them is the Cyber Leader, and the Cybermen were probably ubiquitous enough from novelisations and clips not to be a total mystery to the audience, but, after The Keeper of Traken unveiled the Master without the Doctor being there to recognise him, it’s another example of the show making few concessions to a non-fan audience.

Next episode: Earthshock – Part Two