This is a let down after a lead up of four really entertaining, funny episodes. While Malcolm Hulke has never tried to hide this is a companion piece to Doctor Who and the Silurians, I think here the comparison works very much not in The Sea Devils‘ favour. Partly this is because the dilemma is so unchanged from the earlier story. But largely it’s because the Sea Devils themselves aren’t given the space to become an equal and opposite culture to humankind, as the Silurians were. Instead, the Master takes the place of the arrogant “Young Silurian” in arguing against the elder Sea Devil’s willingness to negotiate, and so the Sea Devils themselves are reduced to props in the ongoing enmity between the two Time Lords. They look quite good, and their whispery, rattling voices are better than the Silurians’ warbling, but the Sea Devils just aren’t as interesting.

It’s also a problem that the humans’ aggression isn’t personified by the Brigadier, and therefore imbued with some sort of ambiguity and nuance. Instead, a brand new character, Walker, is introduced in this episode with so little subtlety or sympathy that Hulke undermines his own moral point. Walker is the worst of the Pertwee-era civil servants so far (yes, even worse than Chinn). He’s entirely hateful, from the moment he arrives pompously declaring his own importance and treating Blythe with casual sexism and patronising Bowman. He treats HMS Seaspite like some sort of backward British colony that he’s been sent to sort out, and condemns men to death while licking butter from his fingers and quoting Shakespeare. His vileness is so complete that we overlook the fact that the Sea Devils have killed or injured several people, and allied with the Master in a plot to conquer the Earth.

So, this is boiling down to a conflict between another bunch of the Master’s alien stooges and a horrible civil servant, lacking in any of the decent characterisation of the last few episodes. Even the plotting is less assured – it’s rarely a good sign when the Doctor spends most of the episode organising a breakout to return to base for one scene before he declares he’s heading back to where he’s just come from. This is a lot better than the last time the Doctor met fish people under the sea, but it’s still not very good.

Next episode: The Sea Devils – Episode Six