Episode 3x13, The Man From Tallahassee
Kate sneaks into the house that she saw Jack go into and finds him playing the piano. He tells her to leave, that they are watching him, but she is captured and taken to a game room.Jack comes in to talk to her and tells her that he wishes she hadn't come back for him. He tells her that he is leaving on the submarine in the morning and is going home. She tells him not to trust these people, but he says he trusts them because she told him to when she wanted him to save Sawyer. Kate wonders what they told him.
Episode 3x14, Expose
In an island flashback, Kate is seen on the beach arguing about the gun case they'd found that she hadn't wanted to tell anyone about.Episode 3x15, Left Behind
Locke comes into the room where Kate is being held to say goodbye. He says that he put in a good case for her, but then they told him who she was and what she had done.Kate wakes in the jungle and realizes that she's handcuffed to Juliet, who is still out. Kate tries to life a pocket knife from Juliet's pocket and Juliet grabs her wrist. She asks Kate what happened. Against Juliet's wishes, they go back to the Others' camp. Before they get there, they have a couple of run-ins with the smoke monster. Juliet acts as if she hadn't known about the monster before.
As the monster chases them, Kate won't cross the barrier of the security fence, so Juliet is forced to pull out a key and unlock the handcuffs so that she can get inside the fence and turn it on. She yells for Kate to get inside and then activates the fence. The smoke can't penetrate the force field.
Kate is mad and Juliet explains that she wanted Kate to feel like they were in it together because Juliet's people had left her and she didn't want to get left behind again.
Episode 3x16, One of Us
Kate doesn't want Juliet to return with them and is upset about Jack sticking up for Juliet.Kate is happy to get back to the beach and she shares a long embrace with Sawyer.
Kate doesn't want Juliet to go get a medical case to help Claire, but Jack lets her go.
Episode 3x17, Catch 22
Sawyer comes to Kate wanting an afternoon delight, but she turns him down. Later, she flirts with Jack. He walks away from her and goes and sits with Juliet. The two look to be having a good time.Kate gets jealous and upset and goes to Sawyer and seduces him.
After Sawyer finds out about Jack and Juliet, he confronts Kate, but Kate says she wasn't using him.
Episode 3x18, D.O.C.
Sun asks Kate if she thinks Jack is working with the Others. Kate says he would never do that and then tells Sun that Juliet is a fertility doctor and that the Others wanted Claire's baby for research.Episode 3x19, The Brig
Kate finds Sayid trying to fix Naomi's satellite phone and asks what it is. Sayid asks if she can keep a secret and as soon as he tells her, she goes to Jack and tells him.Juliet thinks they should tell Kate something, but Jack says no.
Episode 3x20, The Man Behind the Curtain
Kate tells Sayid that she told Jack about Naomi.Kate finds out that Juliet wants to know if Kate is pregnant.
Episode 3x21, Greatest Hits
Kate goes with a group led by Jack out into an open meadow, where he tells them that when the Others come to take the pregnant women, they are going to blow the Others up.Episode 3x22, Through the Looking Glass
Kate goes with Jack's group to the radio tower. On the way, they only hear three explosions from the beach, so Kate concludes that something must have gone wrong.She tells Sawyer that she wants to go back to the beach to check on Sayid, Bernard, and Jin, but Sawyer barely talks to her. Later, Sawyer tells Jack that he's going back and Kate says she'll go, too, but Sawyer says no.
Juliet volunteers to go and Kate watches as Juliet kisses Jack before she leaves.
Later, Jack tells Kate that Sawyer didn't want her to go because he was protecting her. She wants to know why Jack is sticking up for Sawyer and Jack says, "Because I love you."
As they come over a rise, they see that Ben and Alex are waiting for them. Kate checks around to make sure they had come alone. After Jack talks to and then beats Ben, Kate asks what happened. Jack tells her that he let Sayid, Bernard, and Jin get killed.
Later, Hurley radios and says that they are all okay.
