‘Can’t you use your brains for right?’ the Doctor asks the Daleks at the start of the episode. It suggests he’s learned an important lesson since The Survivors and this exchange with Ian:

The Doctor: They’re intelligent, anyway. Very intelligent.

Ian: Yes, but how do they use their intelligence? What form does it take?

The Doctor: Oh, as if that matters.

Perhaps he’s started to realise that there is a moral dimension to his travels, and that he does have a responsibility to his fellow travellers. Certainly, from this episode on he starts to change his tune a bit. It’s an interesting theme, although I’m not convinced anyone watching in February 1964 would have remembered a brief dialogue exchange from December 1963. It’s interesting that he’s now ready to use the TARDIS itself as a bargaining tool, revealing its ability to travel in time and space, and promising to explain its ‘philosophy of movement’ if the Daleks halt their plans.

This is a much superior episode to The Ordeal. There’s a sense of urgency as the Daleks begin their countdown to nuclear Armageddon, and the Thals launch a desperate attack on the city. This contains a first appearance for the classic Doctor Who line, ‘These corridors all look alike.’ They’ve also started to look a bit tatty – presumably, given that The Dead Planet was taped twice, this is the eighth time these sets have been put up, and they’re starting to wear a bit thin.

Also a bit tatty: the final battle. It’s quite weakly directed, with Thals and Daleks stumbling about, as though no-one is quite sure where they’re supposed to be, or what is happening. ‘500 years of destruction end in this,’ says Alydon, as though he’s as disappointed as the audience by such an underwhelming climax. ‘If only there’d been some other way,’ Ganatus adds, in a line I suspect Ian Levine may have suggested including in Warriors of the Deep 20 years later.

The coda is charming: the Thals have access to the secrets of the Dalek city; the Doctor wistfully remembers he was once a pioneer among his own people, and Barbara gives Ganatus a quick kiss before she vanishes into the TARDIS. It’s the first of many endings where the Doctor’s keen to move on, leaving the work of rebuilding to someone else. The morals of this story: use your intelligence to do good; never give up hope; everyone, from Susan and her journey through the petrified jungle to Antodus’ sacrifice to save Ian, has the capacity for great bravery.

Overall, this second adventure doesn’t immediately give the impression it’s the prototype for the future. The slightly worthy anti-nuclear parable is almost like something from Out of the Unknown. It’s the pulp Second World War elements that Nation adds: the reluctant warriors versus the expansionist warmongers, that are in retrospect the bits of the story that get picked up in subsequent Dalek adventures, and which therefore become almost the default setting for other Dalek-wannabe monsters like the Mark 2 Cybermen, the Ice Warriors and the Dominators. I think it’s this combination of worthiness and pulpiness that make these episodes so interesting, and so influential. It’d be a stretch to claim any of them is a masterpiece, but in a fumbling, tentative way Nation has started to put together the pieces of a show that goes beyond Sydney Newman’s conception of a family science fiction series, to becoming an all-encompassing phenomenon. In that sense, he is to Doctor Who what Brian Clemens was to The Avengers: not the creator, but the person who spotted the potential to create something unique.

Next episode: The Edge of Destruction