Thanks to the miracle of Interweb stealery I was able to watch The Changes last week, the ten-part kids’ TV adaptation of Peter Dickinson’s novels from the 1970s. This was always a touchstone of Mr R Carmody’s thinking, so I was eager to see it: of course as soon as it got going I remembered that the theme tune was said touchstone not the actual show.

Which wasn’t bad, once you got used to its peculiar tone and creaking pace. In memory most of the BBC’s 70s and 80s output – until Grange Hill came along, anyway – was like this: sensible and patient children moving thoughtfully through a variety of quite gentle adventures. The oddness in the Changes comes from the fact that the events and dangers of the story are enormous – England thrown back to the dark ages; plague, suffering, anarchy and a constant threat of death – but the heroine, Nicky, paces through them with a stoic, well-brought-up acceptance. Even when she’s about to be stoned as a witch she just looks a bit glum. “But I’m not a witch,” she says, as if she’s been accused of stealing another girl’s pencil case.

It’s not a bad performance though – certainly not set against the mostly wooden guest cast, though the occasional villains get to ham things up nicely. She has presence, and her naturalism lends her authority and gives the whole show a slightly dreamlike quality, so that in the final episode I ended up accepting the completely ridiculous conclusion just because the tone held so steady. It was a big rock pretending to be Merlin all along? Oh, good, glad that’s sorted out.

The adaptation would have been a tricky proposition as Dickinson wrote the books in reverse chronological order – starting with the magic-heavy resolution and then using the other two to explore the human consequences of a world without machines. So telling the story in event order, as the TV series has to, means moving from psychological sci-fi to Arthurian fantasy (hence the fudge at the end with the rock – in the books it’s Real Actual Merlin, and he’s hooked on morphine to boot). Given this difficulty the even keel the series keeps is pretty admirable, even though it means The Changes lacks real excitement.