Wow. In the old days that would have been padded out to three episodes. Excellent, and terrifying.

Our enjoyment may come at a price. Young F was dawdling over bedtime, and after I’d explained why it was not in black and white (unlike the William Hartnell series he has seen me watching) he settled into the programme, and of course wanted to watch the next episode immediately. Well, so do I, but unfortunately we will have to wait until next week! Let’s hope it doesn’t give him nightmares.