I want to say to-day's episode of Doctor Who was about Ashildr and Clara playing Doctor but you'll get the wrong idea. Written by newcomer Sarah Dollard and featuring a show changing event--surprisingly given that the episode isn't written by showrunner Steven Moffat--it's not bad and has a slightly Harry Potter quality.
Didn't the Harry Potter stories have a hidden Elizabethan street like this? I don't remember, I've never read the books and I haven't seen the movies in years. Anyway, there's a definite sense of magic in this episode rather than alien science, even though the latter is what it is.
Oh, that coat. This is it, this should be Twelve's costume, it took us a while to get here but now I think it's settled and we should stick with this. Okay? Okay. I guess part of me did kind of like the shark t-shirt from the beginning of the episode.
So, no, the episode isn't about Jenna Coleman and Maisie Williams exploring each other's bodies (though wouldn't be nice?) but about the two of them trying to be incredibly clever in laying plans and making one little mistake that leads to things going tragically, horribly wrong. I won't weigh in on whether I think this was the best way for this to be settled because I suspect it won't truly be settled until two weeks from now.
The episode also sees the return of Rigsy from last season's episode "Flatline". He feels like a completely different character now with a wife and newborn child, no mention is made of his graffiti art. The actor, Joivan Wade, is still pretty flat but the absolute lack of personality he has in this episode seems to indicate he probably won't become a companion. At least I hope not. I did like the dialogue between him and Clara, though, as she slowly convinces him that her extremely dangerous idea is just an every day bit of strategy. Listening to the two of them talk it's rather hard not to become very, very worried.
The climax of the episode was painful, Capaldi is great, subtle, and restrained, Coleman is good and I liked how at the end she didn't seem to become super wise, compared to the Doctor she really is a kid who's in over her head. I loved when she tells him she never asked him to protect her and he says, "You shouldn't have to ask."