After searching in a tree for food, Kate hears something in the bushes. She hurls a rock, causing Sawyer to jump out of the bushes in pain. When she asks what he was doing there, he claims that he was protecting her. The two then head back to the camp but stumble across a lake with a waterfall. They jump in, and while underwater, find bodies of dead passengers. Sawyer dives down and retrieves a wallet from one of them, and Kate finds a metal briefcase. However, when Kate claims it doesn't belong to her, Sawyer keeps it.
Back on the beach, the waves are beginning to move farther up the beach. Jack, with the hope of finding Claire, asks Sayid to take him to Rousseau, but Sayid tells him that Rousseau is crazy. That night, when Kate sees Sawyer with the briefcase, she has a flashback of a bank robbery occurring when she is applying for a loan. As the flashback ends, Kate tries to steal the briefcase from Sawyer, but he catches her. She demands that he give it to her, but he refuses.
The next day, as Sayid asks Shannon to try to translate Rousseau's notes, Boone brings Locke an axe, and they head off into the jungle to go to the mysterious object. Meanwhile, Sawyer attempts to open the briefcase. When he can't get it open, Michael suggests using force. Sawyer goes into the jungle and tries smashing it against a rock. When that doesn't work, he drops it from high in the air. However, when it hits the ground, Kate grabs it and runs! Sawyer catches up to her and takes it back. He then offers to give it to her if she merely tells him what's in it, but she doesn't. As Sawyer walks away with it, Kate has another flashback. A man rushes at one of the robbers, and the gun falls near Kate. She picks it up but doesn't know how to turn the safety off. One of the robbers then grabs the gun from her and takes her into a room. Once there, the two start kissing!
Kate goes to the cave and finds Jack. Not knowing that Sun speaks English, the two talk openly about Kate's past. Kate tells him that Sawyer has the marshal's briefcase and that it contains guns. She then reveals that the key is in the marshal's wallet. As Rose, who convinced Charlie to help her move stuff from the beach, tells him that what happened to Claire wasn't his fault, Kate and Jack arrive at the marshal's gravesite. Kate then has a flashback about being taken back into the bank's lobby. Using Kate, the robbers convince the manager to open the vault. Jack and Kate manage to dig up the body, and she retrieves the wallet. Upon opening it, she finds maggots and drops it. Jack then picks it up and opens it, but there is no key. He then realizes that Kate dropping the wallet was a distraction to hide that she had grabbed the key! Angry, Jack takes the key from her and walks off.
As Shannon tells Sayid that the translations appear to be nonsense, Jack threatens to stop giving Sawyer medicine for his wound if he doesn't give him the briefcase. After getting it, Jack takes it to Kate and tells her that they're going to open it together. Kate then has a flashback about going into the bank's vault. When one of her accomplices prepares to shoot the manager against her request, she grabs a gun and shoots the accomplice! When he drops his gun, she grabs it and shoots the rest of them! Kate gets the bank manager to open safety deposit box 815, and inside is an envelope. As the flashback ends, Jack opens the briefcase. Inside of it are the guns, some money, and an envelope labelled "personal effects". He hands it to her, and she opens it, revealing a miniature airplane. When Jack asks her what it is, she tells him that it belonged to the man she killed, and she breaks down crying.
That night, Rose and Charlie talk about her husband, who was in the back end of the plane. As Rose tells Charlie that she feels her husband is still alive, Shannon informs Sayid that Rousseau's notes are actually a song.