‘Bring forth the cutting device.’ Even though the set designs look like Princess Leia’s spaceship in Star Wars, I think this is going for a sort of 1980s horror vibe. Replace the shuffling Sea Devils with equally shuffling zombies overrunning a military base and you have half the plot of a Romero movie. In a zombie horror, the traitors Nilson and Solow would cause the complications that allow the zombies into the base – here, they’re little more than local colour, although the warring human power blocs must surely be meant to contrast with the unity between the ‘blood-related comrades’ Silurians and Sea Devils. It’s not just a continuity fetish team-up, it has some relevance to the themes of the piece.

Sadly, this has none of the dynamism of a 1980s horror film. The idea of the Sea Devils wearing Samurai armour is ok, but their helmets just tend to highlight the floppiness of their heads which might have been slightly less noticeable without hats on top of hats. They really do shuffle very slowly, and the scenes of them invading the base, and the humans desperately falling back are shot with all the urgency of a builder finishing a tea break. Combined with the Myrka – which might not be worse than Erato but is exposed in far crueller detail, shots of the Silurians with their latex necks flapping about outside their shells and Ingrid Pitt’s bizarre death jive, and there is a definite sense of “that’ll do” about this.

Again, I don’t hate this, but it’s a thin script executed with very little panache. At least Mark Strickson is being given some stuff in this: he intervenes to rescue the Doctor and Tegan, reluctantly joins the defence of the base, and then pines for the safety of the TARDIS (even though more often than not it’s been a very unsafe place for him to be).

Next episode: Warriors of the Deep – Part Four