Again, all the time spent with the regulars – which is again the bulk of the episode – is good fun. Jamie gets more action this week: trapped in the Dynatrope with the Krotons, he discovers they’re actually quite chatty. Robert Holmes writes them almost as his trademark fusty bureaucrats following the rules rather than being actively malevolent. ‘All waste matter must be dispersed. That is procedure,’ the Kroton Leader tells Jamie. Their heads also spin quite sweetly when they’re agitated.

Clearly some thought has gone into the monsters and their aesthetic. Their heads spin, they have a strange spinning mind control device, and spinning patterns on their monitors. The emphasis on their viewing devices, and Zoe’s creepy feeling of being watched, is especially interesting when it turns out they are essentially blind outside their spaceship and rely on their cameras to ‘see’. Director David Maloney picks up on this detail, and Holmes’ obsession with being watched, to really nice effect – after the Doctor was menaced by a camera eye on a metal snake in Episode One, here Maloney gives us some great Doom POV shots of the second Kroton venturing through the wasteland to hunt the Doctor and Zoe.

This sequence shows Holmes’ unfamiliarity with the show – going back to the TARDIS mid adventure is quite unusual (I can only think of one previous occasion, also from rookie Who writers Haisman and Lincoln, in The Abominable Snowmen). However, it does lead to the scene of the TARDIS being apparently destroyed – which after it ‘blew up’ in The Mind Robber and vanished from The Invasion suggests perhaps Sherwin was building up to writing it out entirely as as part of his planned reformatting.

Sadly, while the regulars and the monsters are quite good value, the parallel plot of the Gonds’ half-baked rebellion, which seems to be more of a threat to the Doctor than the Krotons, is fairly dull. Even Philip Madoc doing his best Paul Darrow grin isn’t enough to lift it.

Next episode: “The Krotons” – Episode Four