Very much a middle episode, this doesn’t quite work. Pertwee spends a lot of it on his back, in a slight return of the classic third Doctor coma trick, which isn’t really a great look for his final story (although Sarah’s loyal vigil is good foreshadowing for Part Six). Instead, we get Gareth Hunt and Ralph Arliss rehearsing the themes of hot-headed action vs measured courage that were tired when Terry Nation did them. We also get several scenes of Lupton’s businessmen associates having a conference at the meditation centre, and Sarah Jane learning the history of Metebelis 3.

The latter scenes are at least constructed well. As Sarah chats to fellow captive Sabor in the Eight Legs’ larder, and learns that the spiders are going to eat them, there’s a darkly comic cut to the Doctor enjoying a bowl of mutton broth with Arak. A few minutes later, we cut back and forth between the two conversations which adds an element of dynamism to what’s otherwise very talky.

Less effective is the Metebelis crystal’s effect on Tommy, turning him from Mummerset simpleton to erudite aesthete. It’s supposed to illustrate Sabor’s point that the crystals can enlarge the mind, as well as linking to the wider theme of renewal and growth, but the equivalence drawn between a common spider and a man with a cognitive disability almost certainly wouldn’t wash today. While I don’t think we should judge the past by the standards of the present, I think this plotline is awkwardly done and I’d question whether it was even effective back in 1974.

I also think the cliffhanger doesn’t work. Lupton spends the episode lurking around, is suddenly arrested in a corridor, and the Doctor is then chased by some guards and captured. This is, apparently, because material had to be brought forward into the under-running third episode, but the result is that a scene that was meant to be a quick bit of business to resolve the original cliffhanger (Lupton yelling, ‘Kill him now!’) has to serve as the climax. It doesn’t.

Next episode: Planet of the Spiders – Part Five