Somewhat later, Mormont is sitting in his chambers when Snow comes in. He tells Snow to bring him a horn of ale... and to have one for himself. The raven has clearly brought bad news. Mormont tells Snow that the king is dead, and that Lord Stark has been charged with treason. "They say he conspired with Robert's brothers to deny the throne to Prince Joffrey." That's not entirely inaccurate, I guess. I mean, he was "right" to do so if you like, but he definitely talked to Renly and sent a message to Stannis to try to keep Joffrey from becoming king. Snow reads the letter and stands. Mormont reminds him that his duty lies here, on this desolate Wall, rather than down south causing trouble. Snow says that his sisters aren't mentioned in this letter, and Mormont speculates that they'll be treated gently. Sure they will.
Sansa Stark is being worked on in King's Landing. But it is, in fact, being done gently. Cersei and Pycelle tell her about how evil Ned has been. Cersei works on Sansa's princess complex directly: "You're the daughter of a traitor. How can I allow you to marry my son?" Sansa swears she'll be a good, obedient, mild queen, just like Cersei. If she had ten percent of Cersei's spirit, I'd like her a lot more. It turns out I like evil characters more than wimps. Littlefinger, presumably reading from the script that Cersei handed out before the meeting, says that Sansa should be given a chance to prove her loyalty. She's told to write to Catelyn and Robb and urge them to keep the King's Peace. And Robb needs to come down to King's Landing and swear fealty. Sansa is a little overwhelmed (because normally all she has to do is look pretty and do some embroidery) and says she just wants to see her father and talk to him. This doesn't go over well: "We've told you of your father's treason. Why would you want to talk to a traitor?" So what, Sansa asks, will happen to her father? Depends on Robb. And on her. Sansa takes the quill.
In Winterfell, Robb is outraged by the note. Say, these ravens are quick, aren't they? The specific word he objects to is "treason," but Luwin says that even though it was Sansa's hand, the words were Cersei's. And it's a royal command. Robb says he'll go to King's Landing, but not alone. "Call the banners," he says, and it's not as impressive as the show thinks it is. Although it turns out that calling the banners means assembling a giant army of people sworn to defend the Starks, so I guess that's pretty good after all. It just sounded like he wanted some flags and bunting. Theon smiles, because I guess he likes to see some action. Luwin goes off to do some banner-calling and Theon asks Robb is afraid. Robb looks at his trembling hand and allows as how he appears to be. "Good. Means you're not stupid." I think he could still be stupid. Just not for that reason.