On their way to Catelyn's tent, she and Brienne chat. The only reason for this discussion is so that Brienne can say she's "no lady" and so we can see how giant she is next to Catelyn. She's pretty big!
Now to Pyke. Home of the Greyjoys. Theon is wandering around the living room, looking at the awesome stone kraken over the fireplace. He notices Yara watching him and gets mad that she's there. Which is weird, as she points out, since she lives there. He calls her a lying bitch. Not for saying she lived there; for not saying she was his sister before he started rubbing his hands all over her on the ride to the castle. She says it's his fault for now recognizing her, but he claims she looked like a fat little boy the last time he saw her. She says that's what he looked like too, but she recognized him. Well, sure. He was swaggering around the dock announcing that he was Theon Greyjoy, heir to Pyke. And he'd probably sent a message saying he was coming. Anyway, she didn't tell him who she was because she wanted to see what kind of man he was. And she did!
Their father Balon enters and delivers a speech heavy with metaphor: "The wolf pup has gone south with the entirety of the northern army at his back. While he's tangling with the lion in the Westerlands, the North is ripe for the taking. The Ironborn will reave and pillage as it was in the old days all along the northern coast. We'll spread out dominion across the green lands securing the neck and everything above. Every stronghold will fall to us one by one."
Okay, I shall now explicate this speech. The "wolf pup" is Robb Stark. He's a wolf because that's the symbol of the Starks and he's a pup because he's young and Balon doesn't respect him. He's gone south with his army to face the Lannister army, which is led by Tywin Lannister. The Lannisters are the lions, and Tywin, as head Lannister (and someone worthy of Balon's respect) is "the lion." With Robb's entire army fighting the Lannisters, the North is undefended. The Greyjoys are the Ironborn and they'll swoop in there and do some reaving and pillaging. The "neck" is just part of the continent.
Balon's goal is to take Winterfell. I like his odds, because I'm not sure Bran, as a crippled little boy, is going to mount a great defense. I guess he could enter a magic dream or something, but it's not clear if he can control the wolves while he's doing that. Plus, I think Winterfell only has the two wolves (his and Rickon's), which is probably not enough to stand off an army. Yara thinks this is a great plan. And why not? She's going to be in charge of thirty longships, which has already been established as a large fleet. In fact, it's the same size as the pirate Salladhor is giving to Stannis Baratheon. So naturally, Theon wants to know how many ships he's going to get to command. He gets one ship, with which he is supposed to raid fishing villages. Yara smirks at him for this. I realize this is mostly because Theon is on the outs with his family, but it also works as a sister-brother thing. And Theon's ship's name is "The Sea Bitch."