User:SOTO/Forum Archive/The Panopticon/@comment-1293767-20151029072618/@comment-5918438-20161207042529

And as an update regarding Class, this would make Co-Owner of a Lonely Heart and Brave-ish Heart a two-parter, while Detained and The Metaphysical Engine, or What Quill Did remain individual stories, as we treat them now.

Despite having the same director, they barely even have the main cast in common, certainly no guest actors. In fact, the best comparison to Doctor Who here is the original double banked episodes. So Love & Monsters and The Impossible Planet/The Satan Pit, and Blink and Human Nature/The Family of Blood. You have one episode (Detained) that's "Quill-lite" and one that's "student-lite" (Metaphysical).

And if the "common setting" amendment seems like stretching the simple rule, it's no loss to consider Heaven Sent and Hell Bent separate. Even the director Rachel Talalay spoke in one interview (uploaded on the wiki somewhere) about how those two were so very different stories. It seems more like a The Girl Who Died/The Woman Who Lived case, where there's a linking element and similar titles, but totally separate plots. Anyway, we shouldn't squabble over individual stories. We want rules that are clear, and then we want to stick to those.