I didn’t intend to discuss these two episodes of Doctor Who together, but watching the first was delayed because I was in Scotland when the first one was on. And I didn’t realise they were a two-parter.

Except (spoilers) — oh, they’re not. They’re the first two of an n-parter, where n equals… who knows? At least three, and I’m sort of guessing from the titles and directors that it might be four.

Anyway, in them we have one really good episode, one not so good.

Episode 6, “Extremis,” was really very good indeed. Right up there with the best of this series so far. And good to get the mystery of the vault revealed early on, rather than letting it drag on to the end of the season and be an anticlimax.

Episode 7, “The Pyramid at the End of the World,” despite the great title, was weaker, largely because of scientific irrationality and foolish plotting. To say nothing of incredibly lax biosecurity.

That said, I did enjoy it while watching it. It’s one of those ones where a little bit more care, a few easily-insertable words, and it would all have held together much better. The problem with bad science or plotting based on foolish mistakes is that they can dump you out of the story. Critical faculties should be engaged after you’ve watched a show, not unceremoniously force-invoked by something happening onscreen.

Never mind, though: the next one looks very interesting.