The episode begins with Elena pulling over her stolen Porsche in the third city in their Katherine search. Elena says she's hungry and goes to feed on a woman on the street. The woman addresses Elena as Katherine and tells her to feed from her wrist not her neck. Rebekah and Elena realize they have stumbled upon Katherine’s hideout. The woman doesn't recognize Katherine's name when Rebekah says it. They figure Kathrine’s compelled people to forget about her unless they were talking to her. The woman tells Elena she had promised they could all be friends as long as they kept her secret, but she doesn’t seem to know what it is.
Stefan and Damon collect Damon's abandoned car on the road. Sheriff Forbes has tracked the girls' stolen car to Willoughby, Pennsylvania. Damon wants the old Elena back because he feels without humanity Elena is stone cold. Back home, Klaus tries to get the stake tip out of his back. Caroline arrives, but it’s actually Silas, who says that until Klaus brings him the cure he will have to suffer. Elena finds Katherine who jumps her, but Rebekah arrives just in time and pulls her off.
They sit down for coffee in a diner and Rebekah keeps Katherine in place by jamming a fork through her hand. She's on Vervane so Rebekah can't compel her to cough up the cure's location. She says she plans to give it to Klaus so he'll stop chasing her. They check her phone and find an appointment to meet "EM" at two. Caroline shows up at Klaus' house. He thinks she's Silas, but she mentions prom and he believes it's her. He points out if she dies, they all die, too. He wants her to cut the stake out.
In Willoughby, the boys find the stolen car. Damon doesn't understand what Katherine is doing in this town. Stefan questions how they're supposed to go up against Rebekah, but Damon is more determined than ever to get the old Elena back and hence doesn’t seem to care about that. Elena dresses up as Katherine, doing her hair and demanding all her jewelry, her jacket and her shoes. While Elena as Katherine is waiting to meet with "EM", the boys find Rebekah and Katherine in the diner. "EM" shows up for his meeting with Katherine and turns out its Elijah. He kisses her and asks if she has the cure with her, but when he sees her daylight ring he realizes the girl in front of her is Elena and not Katherine.
At the diner, Katherine tells them who "EM" is and Rebekah tells them where she is. They realize she plans to use Elijah to broker her deal with Klaus. Back in Mystic Falls, Caroline digs around in Klaus' back with a knife, trying to find the white oak stake tip. She jabs the knife around and hurts him then apologizes. She suddenly realizes something and stops. She offers him a bargain, saying she'll help him if he allows Tyler to come back to town and promises not to hurt him. Stefan calls Elijah from Katherine's phone and they trade threats. Elena tells him he's an idiot to fall for Katherine and believe her. He says that he can tell her humanity is off, but he still seems to trust Katherine.
In order to convince him of Katherine duplicity, Elena tells him that her brother was killed by Katherine. On hearing this, Elijah realizes Katherine lied to him. Katherine brings Damon and Rebekah to her place and says the cure isn't where she left it, but they don’t buy that. Damon looks around and tries to figure where she hid it. He tries the fish tank with no fish in it and finds it full of Vervane water. Katherine shoves Damon’s head into the water, but has to stop when Rebekah arrives. Katherine hands the cure to Rebekah and makes a run for it. Damon is too wounded from his Vervane dunking to stop her. Rebekah looks at the vial in her hand and seems to be contemplating something.
Damon realizes Rebekah is considering drinking what’s in it and tells her to stop. She tells him that her taking the cure is the best thing that will ever happen to him. She reminds him it’s better for him if Elena doesn’t have the cure and drinks it moments before Stephan arrives. Damon and Stephan watch in despair as she collapses on the couch. Back in Mystic Falls, Caroline waits out Klaus's yelling, trying to make him agree to release Tyler. They end up arguing with Caroline saying she should have turned her back on him ages ago. Suddenly, Klaus realizes the pain is gone. It was never there, Silas was in his head and Caroline took his mind off it. He tells her that she brought him back and Caroline wonders what Silas could do to the rest of them, if he can do this to Klaus.
Back in Willoughby, Stefan blames Damon, thinking that he let Rebekah take the cure on purpose, while Rebekah wakes up. Elijah offers his condolences to Elena for Jeremy's death. She can't believe he thinks that the Katherine he used to love is still in there somewhere. She says that Damon and Stefan also seem to think there’s still a part of her (Elena) inside what she’s become. Elijah says the boys can’t be blamed for thinking that because it would be a shame for the world to lose a compassionate soul like hers. She remembers what he wrote to her once about her compassion being a gift, but it felt good to watch that letter burn, along with her old life and Jeremy's body. Suddenly, Katherine appears and snaps Elena's neck.
Rebekah wakes up feeling human and Damon points out it means he can kill her now. He flings a letter opener at her head, but Rebekah catches it instinctively with vampire speed. They watch as the cut on her hand heals quickly, which mean she's still a vampire and the cure was a fake. With Katherine, Elijah brings up the fact that she killed Jeremy and she says it was necessary. She tells Elijah she loves him, but he doesn't believe her and walks away looking completely disappointed. Katherine shows up at the doorstep of the woman from the street. She is there to retrieve her secret package; the cure.
Katherine stops Elijah on the street. She tells him he's right, that she's been on the run so long she's starting to believe her own lies. She shows Elijah the cure, saying she could give it to Klaus and kill him, but she knows she'd lose Elijah and she doesn't want that. She gives him the cure hoping he'll trust her and lets him decide what he wants to do next, while she walks away. Rebekah finds her brother and asks for the cure. She wants to live a simple life as a normal person. She says it’s time for her to live and die the way she chooses to. Klaus calls her and she hands the phone to Elijah. He tells Klaus he's bringing the cure back to Mystic Falls, they'll settle it like family.
Klaus asks Caroline if they can be friends and she asks about Tyler. He points out to her that he isn’t exactly scouring the earth for Tyler, so she needn’t worry. Damon admits to Stefan that he let Rebekah take the cure, but immediately realized it was a mistake. He says he had a moment of weakness like them both falling for the same girl. Stefan says them both loving Elena is like them both liking Katherine, they just keep repeating the same cycle. Once they get the cure for Elena, Stefan plans to go get a life of his own.
They find Elena back at the diner. She tells them she doesn't want to take the cure and wants them to accept it, or there will be consequences. Stefan reminds her about her rescuing him from the brink when his emotions were off. The waitress comes to refill Elena's coffee and she snaps her neck, killing her. She warns them if they keep at it, there will be more. The episode ends at this point.