Oh good grief it's another wedding. Hold onto your hats everyone! It's mostly a dull affair this time around, though. Cersei doesn't love Jaime any more. Word is getting around that the Hound has joined Lord Beric. But not that Catelyn has. Cersei remembers going to see an old fortune teller called Maggy who promised that Cersei would be queen until a younger queen came along to replace her. It's not exactly the prediction of the decade, that one, is it? But it makes Cersei paranoid about Margaery. But she probably should be. Margaery does seem particularly smooth with the social graces, in an annoying and suspicious way. And Cersei is told that one of her personal assistants is spying on her for Margaery.
To liven up proceedings, Cersei burns down a tower with magnesium. Then she sends Jaime off to make sure Margaery doesn't attempt to consummate the marriage, and goes herself to consummate something with a Kettleblack. Jaime will be happy, then.