Sansa arrives by ship to Petyr "Littlefinger" Baelish's family home. He makes much about how humble it is. Lots of revelations in this chapter. First we learn that Cersei's Kettleblacks were planted by Petyr and they are really beholden to him. Their dad is one of his servants. So that explains their mysterious (and largely fake, I would imagine) background.
And we find out that the hilarious old lady Tyrell poisoned Joffrey! I knew it! Sort of. What annoys me is that I didn't notice until now about the hairnet-straightening. All the clues were there all along. I could have worked it out. Argh! It makes sense though. Apparently the Tyrell's knew all along what Joffrey was like (since Petyr had his servants spread rumours about him). We are also supposed to believe that Petyr planted the idea of making Loras a kingsguard just so that the Tyrells would expect the combination of Loras + Joffrey + Maergery would be such a kingslaying recipe that it would be better to just poison Joff upfront and have Maergery marry Tommen instead. How many dimensions of chess is he really playing? He seems like the best informed character anyway. I suspect his analysis of Cersei, that she only thinks she is clever and powerful but is in fact predictable and weak, is correct.
Sansa's aunt turns up. Petyr marries her. They're off to live at the Eyrie. But Sansa has to pretend to be a bastard girl until Tyrion is executed for Joffrey's murder (also planned by Petyr, helped by the dwarf jousting he organised), then she can marry her cousin, the sickly Robert who Lysa has raised to be a complete pussy, almost to the point of child abuse. That sounds a bit yuck but I can sort of imagine Sansa is learning a lot and will eventually be able to manipulate him and get more powerful. Except I think Tyrion may live longer than they expect, unless Petyr has also fixed the trial by combat somehow. Is their anything not caused by Petyr? Or Petyr and Varys? Is that the moral of the story? Some people are players, some are pieces, and it's not who you expect. Sir Humphrey is the real power, the Prime Minister is the piece.