Jack comes home and overhears Kate on the phone making some kind of social plans. She tells whoever it is that she'll have the nanny stay late and that she can stay for at least an hour. She ends the call when she sees that Jack is home. They make some small talk, and he asks her who she was speaking with. She claims it was Noreen, one of the mothers from the park. He clearly doesn't buy the story, but she is cool as a cucumber. Kate heads upstairs, and Jack takes a couple of clonazepam with a beer.
Jungle. Claire, Sawyer, and Miles are sleeping around a campfire. Really, you leave the fire burning while you sleep? These guys are a threat to the island. Claire wakes up with a start when she realizes that Aaron is not nestled in her arms. And then she looks across the fire and sees Christian holding Aaron. I guess if they left the fire burning for dramatic purposes, it's okay. Claire is startled to see Christian, and can only say, "Dad?" Just in case you forgot that Christian is also her father. But, shhhh, Jack doesn't know that. Commercials.
Bernard emerges from the surgical tent and finds Kate sitting on the ground waiting. He tells her not to worry; Juliet was great, and said that Kate can go into the tent if she wants. So she does, and finds Juliet still stitching Jack up. Juliet gives her a quick update of the surgery (prognosis: A-ok), and Kate is thrilled to hear that he should be fine. Juliet apologizes for yelling at Kate, and then tells Kate that Jack kissed her. But Juliet wants Kate to know that she thinks Jack did it because he was trying to prove he doesn't love someone else. Kate thanks Juliet for saving Jack's life. Kate leaves, and Juliet tells Jack that she knows he's awake.
Jack is sitting at home when Kate walks in the house, having just come from somewhere else. He says "hey," and she jumps, startled. She clearly wasn't expecting him home so soon. She asks where the nanny is; Jack sent her home. Kate sits down on the sofa and notices that Jack has several empty beers and a bottle of hard liquor on the coffee table. And then Jack tries to get Kate to tell him where she was. It's all kinds of hostile. Kate claims to have had errands to run. She asks him what's going on, and he tells her that he went to see Hurley the week before. And then he asks again where she was. She asks him to trust her and leave it be. But I guess all of the Jack's time on the island left him feeling question-deprived, because this is one question he wants the answer to. He keeps pressing, getting louder and acting drunker. Kate finally tells him, "I was doing something for him." For who, you ask? Well, so does Jack. Kate: "For Sawyer." She made him some kind of promise before leaving the island, but she never tells us exactly what the favor was. Jack can't believe that this fucking triangle is still going on, even after Sawyer made a decision to stay on the island. Kate's crying, and she tells Jack that if he's going to act all hostile and drunk, she can't have him around her son. Jack: "Your son? You're not even related to him!" But it's not clear whether Jack knows that he is. And guess who woke up to hear that little speech? Yes, that's right, Aaron. The little tyke is standing in the doorway, clutching a stuffed orca and looking kind of upset. Kate picks him up, and Jack leaves. Well, that was a short engagement.