When I was much younger, I didn’t get all the fuss about Douglas Adams. And if I squint I can sort of see why this didn’t impress me much: there’s not really a monster (well, Polyphase Avatron, I suppose), and there’s not a great deal of action. What went over my stupid child head is both the wittiness of the script and the cleverness of the delivery. Watching it now, I can see the whole 21st Century series coming into focus. Romana is River Song, piloting the TARDIS. The Doctor plays the fool, but there are centuries of wisdom behind it, with a burning curiosity and moral authority (he cares about Calufrax, even having dismissed it as boring). The Doctor’s backstory is almost casually revealed (he stole the TARDIS 523 years ago). They’re pitched as equals: Romana even gets to offer around the jelly babies (lifted from the Doctor’s pocket – she must have been learning his technique since The Ribos Operation).

The script is brilliant. Obviously the Captain’s creative invectives are amusing. But pretty much every scene has a quotable line. Particular favourites include K9 telling the Doctor that Romana ‘is prettier than you’ (‘Good looks are no substitute for a sound character’). Lynsey de Paul lookalike Mula (any minute I expect her to launch into a duet of Rock Bottom with Pralix) laments, ‘Why? Why? Why? Why? Why?’ and her grandfather retorts, ‘Don’t spoil everything by asking so many questions.’ It’s obviously a comedy, but it also has that Hitch Hikers Guide aesthetic where huge SF ideas are lightly tackled in an immensely accessible way. Has there ever been a more evocative description of the TARDIS’ arrival than, ‘For 10 seconds the whole infrastructure of quantum physics was in retreat’?

Impressively, by and large the show pulls this off. Maybe that shouldn’t surprise me given how hard director Pennant Roberts worked to get it made, but it would have been easy for everyone to play this for cheap laughs as per The Invisible Enemy. But generally everyone is being funny without pratting about. For example, Andrew Robertson delivers the laughs while also managing to make Mr Fibuli seem genuinely unnerved by the Captain. And the Captain seems like a bombastic, over-the-top villain except for the moment when he wistfully tells Avatron, ‘Not long now before it’s finished, we’ll be free’. And I really like that this echoes a moment elsewhere in the episode where Balaton tells Mula, ‘You think you have no freedom now? You ought to have been here under old Queen Xanxia’, seeding the idea of the real tyrant against whom everyone is battling for freedom.

There are only a couple of moments that really don’t work for me. The location filming of the Mentiads marching across some overcast moors is difficult to square with the brightly-lit Mediterranean-looking architecture of Zanak. And the Mentiads don’t come across as evil zombies with terrible powers. While that’s deliberate, it’s a shame they couldn’t at least have looked a bit more threatening.

Next episode: The Pirate Planet – Part Two