At the weekend we watched the Doctor Who story Full Circle. Now best known for introducing ill-fated (and ill-acted) boy companion Adric, this was a massive hit with me at the time (1980) because of its central plot twist. Which I’m about to spoil beneath the ‘read more’ link.

The story takes place on an idyllic tropical planet which is host to a crashed spaceship, whose inhabitants have been working for generations to repair it. Every fifty or so years their efforts are disrupted by an event called ‘mistfall’, during which the climate changes and the planet’s shambling, monstrous ‘Marshmen’ natives emerge to harass the spaceship folk. The shapeship people hate the Marshmen and consider them barely sentient savages.

The twist turns out to be that the current spaceship denizens are actually evolved Marshmen, the real crew having been killed centuries ago. Age 7 I thought this was amazingly shocking and exciting, and I still think Full Circle is a neat, tight story despite the fact that evolution works nothing like that.

Well, physical evolution doesn’t. For the Full Circle effect in cultural action you need look no further than the Indie Kids thread, where the indie nation are recoiling in disgusted horror at the idea that they may be descended from emos. (Adric, obviously, was Math Rock).