"Cracks in time, time running out... No, couldn't be. How is a duck pond a duck pond if there aren't any ducks? And she didn't recognize the Daleks! Okay, time can shift. Time can change. Time can be rewritten... Ah! Oh!"
Ah oh, indeed. The soldiers describe the Crack thusly, for Amy's benefit: "It's like, I don't know... A curtain of energy. Sort of shifting. Makes you feel weird. Sick." Amy keeps threatening to open her eyes up just for a second and look at the Crack, and of course they finally point her in the right direction and she confirms that it's the same shape as her bedroom wall Crack from the olden days, and the soldiers try to get her to close her eyes, and then more of them hustle into the breach and never existed. Amy is able to grasp this concept, but not how it's a super-magical Crack that's following her and is the same shape as this previous other super-magical Crack in her bedroom. To be fair she hasn't seen it flying directly out of her TV screen at her face like one million anvils each and every week, but it still doesn't seem that complicated to me. She also doesn't seem to grasp the idea that if she doesn't close her eyes again, she will die, but again -- to be fair -- that is stupid. Maybe Amy isn't paying attention for the same reason I'm finding it so difficult.
The Doctor is annoying and fugued out, bugging Octavian and doing math in the air: "Time can be unwritten," he says all in ellipses, while Amy has another conversation about the soldiers that don't exist anymore back at basecamp, and here's what he says: "It's been happening and I haven't even noticed! The CyberKing! A giant cyberman walks over all of Victorian London and no one remembers... Never mind the Angels. There's worse here than Angels!" Then suddenly an Angel has Octavian in a headlock, and there's nothing the Doctor can do about it. Apparently. The music would have you believe this is tantamount to the end of the universe, but if the overcooked score doesn't bother you by now, it's never going to.
Octavian immediately slides into the old "There's no way out of this. You have to leave me!" which is annoying every single time and has already happened fifty times in this story alone. Luckily he takes some time out of dying so that he can explain a bunch of shit without actually explaining anything, and here's what he says: "River Song. You think you know her, but you don't. You don't understand who or what she is. I've told you more than I should... She killed a man. A good man. A hero to many. You don't want to know [who], sir. You really don't." He has a sort of heroic death scene that would be really great -- such a fabulous character, and actor -- if it weren't so random and shoved into everything else, and if the stakes weren't on roids like usual and if everything weren't so hysterical and screamy for no real reason.