Snow suggests that maybe they should be sleeping during the day themselves, since they'd just decided to act more like the wildlings themselves. But that won't work because unlike the actual wildlings, they don't know the terrain and would fall into a crevasse in the dark. They talk about how they're at war. Big deal -- everyone on this show is at war. Qhorin asks if Snow is prepared to lay down his life, but it's a trick question. He wants Snow to fight and struggle before he dies all so the people south of the wall will be alive because some nameless bastard gave his life. And when Snow says he understands, Halfhand backs off, saying they're just words. I think Qhorin is imagining himself as a brilliant mentor here, but really he's just being a jerk who negates everything Snow says.
Off to Harrenhal, which I think is my favorite plot location at the moment. Arya and Tywin are both lots of fun. Tywin is engaged in a common hobby: berating his council for being dopes. Here's what this one guy did: "This letter detailing our inventory movements was meant for Lord Damon of House Marbrand. It was send to Lord Marlym of House Dormund." This sounds like a hilarious misunderstanding! Tywin tells Arya to get the Lineage of the Greater and Lesser Houses and Arya accidentally reveals that she can read when she grabs the book before he tells her which one it is. Actually, I think if Tywin had been fully paying attention, he would have realized that she knew which book it was before she even had to read the title. Tywin makes the dummy tell him that House Dormund owes allegiance to House Stark, so this is a bad mistake. He dismisses this dope. To be fair, that's sloppy work. You're not supposed to send vital military information directly to your enemies. He has Arya put the book away. He also jocularly (for him) suggests that she devise the next battle plan.
And then! Littlefinger's here! To see Tywin! Boy, Littlefinger sure travels quickly. Everyone else is largely stuck in one spot, but Littlefinger went from King's Landing to Renly's camp and then came back to Harrenhal without being molested. Everyone leaves and Tywin tells Arya to clear up the room. She gets very nervous, because Littlefinger has actually met her face to face. And what if he recognizes her? He might reveal her to Tywin! Or -- and I don't think Arya realizes this is an option -- he might "hide" her inside one of his brothels, which: gross. She tries to avoid his eyes as she cleans the table and brings him wine, which makes for interesting visual choreography as the rest of the scene plays out.