It’s a bit muddled, but the moral of the story seems to be that appeasement is always an inadequate response to tyranny, and that pacifism is a worthy but impractical principle faced with the reality of the strong seeking to dominate the weak. It’s the same argument the first Doctor and Ian had with the Thals way back in The Daleks. And that’s not the only thing that’s reminiscent of a Terry Nation story: the Dominators’ plan to drop a bomb into the planet’s crust is straight out of The Dalek Invasion of Earth – as is the resolution (the motive – to explode the planet and use the remains as fuel – is novel, but resurfaces in Aliens of London)

Each episode of the serial has just enough incident and humour to make it less than a chore to watch. Troughton is on great comic form again this week, playing the absent-minded professor twice – once when he forgets that his home-made bomb is about to explode, and again when the island of death erupts into a volcano and Jamie has to remind him where they’re standing. The sonic screwdriver also reappears – and this time it’s capable of creating a massive hole in a concrete wall.

There’s also some fairly good scenes of Jamie and Cully attacking the Quarks (and an odd moment of Ewok-style pathos when one Quark is injured and two of its comrades waddle over to look at it). And Toba has finally learned his lesson, refusing to let the attacks distract him from his job of drilling a bore hole for the ‘atomic seed’ (which leads to the immortal moment when Zoe declares, ‘He’s putting it in now!’). Very Freudian.

Going into The Dominators I was prepared to be underwhelmed, and I’m definitely not ready to re-evaluate it as a classic. But both of Haisman and Lincoln’s earlier serials were very good, and while this is easily the weakest it’s not the disaster I was expecting either. It’s certainly too long – it’s hard to imagine another episode adding anything except more of Rago seething and the Dulcian Council prevaricating – and the script doesn’t have enough wit. But part of the problem is Morris Barry’s fairly leaden direction (as usual, his film sequences are a lot more dynamic than the studio scenes), and the fact that none of the guest actors seem to realise it’s meant to be funnier. I definitely think it’s more interesting than The Wheel in Space. But after 17 weeks of pretty slow episodes, there’s a real sense of the show gradually running out of steam. What it needs now is a pretty radical shake up.

Next episode: The Mind Robber