The frustrating thing about this adventure is how nearly it resembles what are going to become one of the archetypal styles of the show. The small cast of human characters, isolated and besieged by threatening aliens, creeping round gloomy spaceship corridors and battling mental possession are all characteristic of half a dozen Patrick Troughton serials. While The Unwilling Warriors is much less formulaic than those later stories, it’s also much creakier, and Mervyn Pinfield doesn’t take advantage of some of the potential scares implied by the script. For example, the Sensorites are effectively creepy, especially when they advance, silently and relentlessly, on Ian and Barbara. But once they start talking, that menace dissipates, and it doesn’t help when the Doctor starts comparing them to cats and surmising that they’re afraid of the dark. You can’t really criticise this for not being made in 1966, but it does suggest the production team didn’t really know quite what to do with this.

Instead, we get something that’s like the precursor to Out of the Unknown, with a very serious focus on telepathy and mind control. Having been sidelined in The Keys of Marinus and practically written out of The Aztecs, Carole Ann Ford gets her first substantial material since Marco Polo, acting as the psychic conduit to the Sensorites. She comes up with the idea of creating a telepathic barrier to prevent the Sensorites from controlling her or Barbara, and she gets a neat little story about the telepathic plants of Esto. The cliffhanger, when she agrees to accompany the Sensorites to their planet providing they spare the others’ lives, is the first time she’s had much real agency since she tried to unmask Tegana.

The rest of the TARDIS crew have settled into their standard roles: Barbara, the caring, practical one – looking after John and asking Ian whether he really needs to be so aggressive towards the Sensorites. Ian gets a science teacher moment as he looks at the results of the spectrograph, and elsewhere is the ‘muscle’. The Doctor gets to take control, pit his wits against the enemy – clutching his lapels to give the Sensorites a dressing down, and delivering the funniest line:

Captain Maitland: Did you know his hair was almost white?

The Doctor: There’s nothing wrong with that

I get the sense that between the last episode and this one, the production team is trying to re-establish some of the basic principles of the series. Last week we had a recap of the ‘story so far’, and this week we get an exchange between Carol and Barbara that’s the first time in ages that we’ve been reminded of the original premise of the show:

Carol: You’ve come from nowhere and you seem to be going nowhere.

Barbara: We’re very dependant on the Doctor. He leads and we follow.

Carol: Travel without a purpose?

Barbara: Oh, no, there’s a purpose in it. He’s trying to get us back to our own time. On Earth

Given the next serial starts with the TARDIS allegedly returning to 20^th Century Earth, and then both of the subsequent adventures in the first production block revolve around either being back in the 1960s (but miniaturised), or back in London (but in the future), I wonder if there was a conscious effort to revive the time travellers’ sense of purpose.

Other things to notice: presumably the lack of TARDIS scenes this week has enabled the addition of more bits of spaceship set. This massively works in the episode’s favour, because the problem of having to stage hide-and-seek scenes on one tiny corridor is gone. Hartnell is much more on top of his lines, but there is one nail-biting moment when he’s trying to remember the relative melting points of iron and molybdenum. He succeeds but the strain of it means he completely stumbles over his next lines.

Next episode: Hidden Danger