Stefan arrives after the police and Elena explains what's going on. Stefan looks Jeremy over and announces he's not a vampire, though he warns him that if he tries to kill himself now, he'll really die. Anna's blood protected him from any harm the pills might have caused. Elena goes to the hospital to check on Caroline and Stefan stays with Jeremy.

At the hospital, Matt tells Bonnie about the noise Tyler heard when he was driving and that Caroline isn't doing well. Sheriff Forbes tells Damon that Mayor Lockwood is dead and they think he was a vampire because he dropped when John's device went off, but she doesn't believe it. In the hallway, Damon suggests to Elena and Bonnie that he give Caroline some blood, just to heal her. Elena's against it, but Bonnie tells him to do it. After Bonnie leaves, Damon tells Elena they should talk about what happened at the house, but she has no idea what he's talking about. Jenna joins them and Elena asks her where she's been. Jenna reminds Elena that she told her earlier that she was going to the fire department. This is news to Elena, and they argue about whether Jenna really told her this. Watching this miscommunication come to light, Damon figures out that Katherine is back.

Katherine enters the Gilbert house through the door and, pretending to be Elena, hugs Stefan, but he realizes that something is off and he is not hugging Elena. He throws her across the room after she tries to kiss him. They fight in the living room until, hearing someone at the door, Katherine throws Stefan down and leaves. Damon and Elena arrive and the three of them catch each other up with what they know. Damon points out that Katherine left Elena alive, so that's not what she's after. Stefan asks Damon what Katherine meant when she said that she fooled one of the brothers. He tells them about the kiss. Stefan is ready to fight Damon, but Elena reminds them they have more important things to worry about. Damon suggests they ignore Katherine to draw her out.

At the hospital in the morning, Bonnie checks on Caroline, who appears to be making a fast recovery. Liz talks to the mayor's wife, Carol, and asks why the mayor was affected by the Gilbert device. Damon cools down the heated conversation. At the mayor's wake, Tyler welcomes back his father's younger brother, Mason, who had been estranged from his brother for several years. Elena and Stefan go talk to John at the hospital. Elena places the ring in John's hand and asks him why Katherine is here. He can't stand the sight of Stefan with Elena and tells them to leave. Elena walks out but Stefan pauses before he aggressively pins John down by the neck, bites himself in the arm, and force-feeds John his blood. Stefan threatens John that if he doesn't leave town within 24 hours, he'll turn him into a vampire and watch him hate himself.

At the mayor's wake, Liz informs Damon that Mason wants nothing to do with the council and he isn't a believer like John. Katherine stops by the wake after Tyler invites her in. Outside the hospital, Stefan admits that he threatened John and told him to leave town. Elena approves. At the wake, Bonnie tells Damon that Tyler was also affected by the Gilbert device. He thinks she's feeling guilty that Caroline was hurt when it went off. She promises that if Damon makes one wrong move, she's going to take him out, and demonstrates her power by painfully bursting the blood vessels in his brain with magic.

Bonnie meets Katherine on the front porch and, thinking she's Elena, complains about Damon. When Bonnie touches Katherine's arm, she immediately knows something isn't right. Making an excuse to get away, she moves to another room and calls Elena, who tells her she's not at the Lockwoods' yet. When Bonnie turns around, Katherine is behind her. Katherine tells her she's putting all the pieces of Elena's life together. Bonnie tries her headache trick but Katherine brushes it off and grabs Bonnie by the throat. Bonnie uses her powers to fling open the doors so people can see them and Katherine finally backs down when Stefan appears. She enjoys people thinking she's Elena. He asks her what she wants, but she's coy.

Jeremy, Jenna and Elena arrive at the wake. Elena goes to talk to Damon. He thinks she's worried that Katherine will send him off the deep end, but he pretends to be fine. She's not surprised he would kiss her; she's surprised he would think she'd kiss him back. Jeremy finds Tyler sitting alone drinking from a flask. Tyler reveals to Jeremy that he thought his dad was a "dick"; Jeremy agrees. Tyler hands Jeremy the flask right when Mason walks in. Mason takes the flask and asks Jeremy to leave. Mason takes a swig from the flask before giving it back to Tyler.

Katherine and Stefan take a stroll outside. He tells Katherine that he was never in love with her because she compelled him, but Damon's been obsessed with her for 145 years. He asks her to get on with whatever she's up to. Katherine confesses that she came back for him, to which he responds that he hates her. Katherine retaliates by pulling a nearby waist-high candle holder out of the ground and stabs him through the gut. She tells him that sounds like the beginning of a love story, not the end.

Later, Elena tends to Stefan as he heals. Damon shows up and teases Stefan about his "crazy ex" issues. When Elena leaves, Damon tries to goad Stefan into fighting by mentioning the kiss again, but Stefan says Katherine is going to pit them against each other and he won't fall for it. He thinks the fact Damon feels something for Elena is a good thing, because it shows he cares.

Back home, John packs up his belongings. He says goodbye to Jeremy, who doesn't understand where John's hate comes from. Jeremy asks him why the ring didn't protect his dad and John reminds him it was an accident, and not a supernatural death. Tyler looks at a picture of his family and smashes it. Mason tackles him after Tyler brushes his mom aside, telling him to calm down. Damon comes home to find Katherine there. She tells him she's leaving, and he asks what she's up to. She taunts him, tellng him to kiss her or kill her. She tackles him to the ground and crawls on top of him. He throws her off but then starts kissing her. As she starts pulling Damon's clothes off, he tells her to stop. He has a question and if she answers it right he promises to forget the last 145 years. She already knows the question and the answer. She tells him that she never loved him, that it was always Stefan, and she leaves.

Elena finds Damon waiting in her bedroom. He's sulking, and drunk. He brings up what she said earlier, about being surprised that he would think she would kiss him back. He tells her she's lying to him and Stefan and herself. He kisses her, but she pushes him away. He persists and she pushes him away again. Finally she tells him she cares about him but loves Stefan, and that it will always be Stefan. Damon, rejected in one night by the two women that he has loved, doesn't take it well. He sees Jeremy in the doorway and asks if he still wants to be a vampire. Before Jeremy can answer, Damon snaps his neck and leaves without another word. Elena clutches Jeremy in horror, sobbing hysterically, until she looks down and sees he's wearing the Gilbert ring.

At the Lockwood house, Mason talks to Tyler about learning to control himself. Elena cradles Jeremy as Stefan tries to convince her that the only reason Damon went after Jeremy was because he saw the ring, but  Elena insists that she hates Damon. Back at the boarding house, Damon is left alone with his rage.

In the hospital, a healed Caroline wakes up to see Katherine standing over her bed. Katherine wants her to give the brothers a message for her: "Game on." She takes a pillow and holds it over Caroline's face until she stops struggling.