‘They’re all dead, you know.’ After the survival horror of Part Three, this is more like the last episode of Robot, with the clock ticking down to Armageddon while the Doctor tries to come up with a solution to the inhuman menace. It gives it a bit more urgency, even if the solution was heavily signposted in the first episode, and a huge amount of this one seems to consist of people getting leg ups. To be fair after moaning about it in the first episode, the floodlighting is really only a huge issue on the bridge set: I still think they could have turned them down, but once the attack on the base begins there’s some effort to generate some atmosphere.

So, I don’t think this is an outright disaster, but it has massive problems. Once again, the writer assumes that the audience is intimately familiar with the show’s history. He might have got away with it when bringing back the Master or even Omega (thanks to The Five Faces), but the Silurians and Sea Devils appeared in two stories a dozen years earlier and I don’t think the script does enough to articulate what they are. I buy that the Doctor will generally prefer jaw jaw to war war, but I don’t like the reliance on (dodgy) continuity to justify it here. It also leads to some dialogue that seems to miss the point that the Silurians and Sea Devils are also Earthlings: ‘I sometimes wonder why I like the people of this miserable planet so much. The Silurians and Sea Devils are noble races. They have skills and talents you pathetic humans can only dream about.’

Ending it with a massacre partly initiated by the Doctor (though he tries to stop it too late) also feels like a betrayal of the moral of the Hulke stories – an admission that ‘there should have been another way’ to the Brigadier blowing up the Silurians, or the navy destroying the Sea Devils, but there wasn’t, or at least there wasn’t one Byrne or Saward could imagine. It makes the Doctor’s victory look pyrrhic if he only wins standing on a pile of corpses, and it’s an ominous sign of things to come, of too many stories over the next couple of seasons that end with the Doctor walking sadly away looking broken or defeated.

So: a downbeat story of mutually-assured destruction, coupled with bad design choices (here, bubble wrap is used to make the beds look futuristic), flaccid direction, some absurd acting (Tom Adams is doing the Sci Fi Voice). I was wrong, maybe this is a disaster.

Next episode: The Awakening