Memory Lane
Stefan and Katherine dance at a party. Stefan notices Damon talking to Elena and follows them out. Suddenly he's back in present day, watching Damon kiss Elena in the grill. Katherine is behind him, telling him now he knows how she feels. "Don't fight it Stefan, you loved me once, you can love me again," she says.
She promises him they'll be together again. He starts awake in bed with Elena and tells her to go back to sleep. He relaxes for a minute, then he leaps out of bed -- it's Katherine.
She tells him she's getting better at getting in his head. He asks why she's back. She says because of him.
Damon sneaks up on Elena in the restaurant. She packs up her stuff to leave. He'll see her later at Jenna's barbecue. He takes credit for the idea, saying it seemed like a good way to get to know Mason since he and Jenna went school together.
He plans to put some silver in Mason and prove he's a werewolf.
Mason dodges Tyler at home. Finally he says: "Yes, I turn into a wolf; no, it's not going to happen to you."
Mason tells Tyler he won't trigger the curse, but won't tell him how not to. Tyler mentions the moonstone and again Mason acts like it means nothing. He leaves. Tyler takes it out of his pocket.
Stefan comes home to find Elena drinking Damon's private human stock. She knows about the werewolves and reminds him the Lockwoods are the ones who rid the town of vampires in 1864.
Flash back to Damon toasting George Lockwood in 1864, and Henry pulling Katherine aside to tell her vampires weren't responsible for the recent attacks. He tells her people were torn apart in ways he'd never seen. She promises him she won't let anything happen to vampires.
In present day, she tells Stefan that the werewolf gene runs in families, but it doesn't mean they're all werewolves. She thinks Stefan came back to town to fall in love with her again. He races close to her and looks deep into her eyes. "What is it about you that makes me still care?" he says.
He kisses her, then he stakes her in the back.
He carries her down to a basement and chains her to a chair, asking again why she's back. She says, again, for him.
He picks some vervane and holds it to her skin, burning her.
She tells him more about the past, George Lockwood approaching her at the party. She tells George point blank that she's a vampire and she knows his secret.
Stefan asks what George wanted.
Back in present day, Mason and Jenna get ready for the party, which she mentions was Alaric's idea. Mason introduces himself to Damon.
Elena leaves Stefan a message.
Caroline sits down with Elena and talks about how hard fighting the urge for blood is. She mentions that Stefan feels the same way about being around Elena.
Back in the basement, Katherine asks about Elena. Katherine insists to Stefan that he still loves her.
Back in the past, Stefan takes Katherine home from the party. She's staying with them supposedly because her whole family died in a fire. Stefan confesses that he thinks she's an angel and he's never met anyone like her. He tells her he loves her and she says there's a lot he doesn't know.
She goes back to her room and Damon's already waiting. He heard what Stefan said, but won't go until she compels him.
In the basement, she tells Stefan no matter what he does to her, their love was real.
At the party, they play Pictionary and Mason guesses Damon's "Dances with Wolves."
In the kitchen, Jenna preps cake and Damon notices her mother's silver set.
In the basement, Stefan says he remembers her compelling him. She says it was only to take away his fear. She says George Lockwood used the vampires to cover his own tracks, but he was willing to make a deal.
In 1864, Henry tells Katherine he talked to Guiseppe Salvatore and round-up plans are set for the evening, 27 vampires will die in a fire. She can escape through the exit under the choir loft, she needs everyone to think she died, too.
Stefan is aghast that she sold them out.
Damon sets pie down on the table with silver pie server. Mason sees it and uses his hands. He sees Ric staring at him and excuses himself as an "animal."
They talk about high school and Damon says he assumed Mason was a "lone wolf."
"I'll bet I wasn't half the lady killer you were," Mason says.
Upstairs, Elena is worried about not having heard from Stefan. She wants to go to his place. Caroline offers to drive her.
Outside, Caroline gives her tire a flat before she gets in.
Stefan thinks Katherine was running from her past. She explains that he nearly ruined her plans for escape. She saw him one last time and bit him, but his dad had poisoned his blood with vervane.
We see Stefan and Damon getting her from a carriage and both of them being shot.
He thinks he died for nothing, but she says it was for love.
Back at Jenna's, Damon busts out a "barking up the wrong tree" on Mason and he gives. He says he wasn't trying to kill Stefan, he has no control when he turns. He says he's not there to hurt them. They shake on it. Mason leaves and Damon grabs a silver knife.
In the car, Caroline babbles about the low ratio for success for vampire-human couplings. Caroline pulls over as her tire goes
Mason says good night and Damon leaves right after him.
On the side of the road late at night, Caroline tries to keep Elena from leaving. She tells Elena her relationship with Stefan is doomed because she'll get old and he'll "still be smoking hot," and they can't have kids. Caroline tries to get Elena to stay, but she walks off when the tow truck driver arrives.
Mason pulls up to the bar. He sees Damon in the street. "What, more dog jokes?" Mason asks. "It got old," Damon says, as he stabs Mason in the chest with the silver knife. After falling to his knees, Mason pulls the knife out, apparently not badly hurt.
"I figure it was vampires who started the myth about silver," Mason says as Damon realizes he has a problem. "Duly noted," Damon says, diffusing.
Mason tells Damon he's made an enemy.
In the basement, Katherine says she'll snap Elena's neck if she has to. Stefan breaks off a chair leg and threatens to stake her.
Katherine says if he doesn't stop seeing Elena, she'll kill everyone Elena loves while she watches and then Elena while he watches. He grabs her again, warning her not to think he won't kill her.
She fights back, easily breaking her restraints. She tells him she's been sipping vervane every single day for the last 145 years.
Upstairs they hear Elena come home. Katherine stakes Stefan through the leg and goes upstairs. The doppelgangers meet.
Elena can't believe how alike they look. Katherine toys with her. Stefan comes upstairs and Katherine leaves. They're both rattled.
At the Mystic Grill, Katherine wants to know how Caroline failed to keep Elena occupied. Katherine reminds her she already killed her once and can easily do it again.
Mason comes home and Tyler casually mentions the stone again. Mason's sick of him playing around. Tyler wants to know what triggers the curse. Mason finally tells him you have to kill someone.
Caroline sees Elena at the grill and apologizes. Elena says she was right, but it's hard to hear.
Elena and Stefan sit at a nearby table at the grill. Elena tells Stefan she's not afraid of Katherine, but he thinks she should be. Caroline hears their whole fight about what to do with Katherine. Stefan says Katherine has already come between them.
Elena leaves. Pan over to see Damon sitting nearby, within earshot.
Damon leaves the grill to find Katherine waiting outside. She asks why he's pouty. "Tried to kill a werewolf and failed, I feel like I'm not living up to my best self," he says. She knows a little something about werewolves.
Back home, Elena finds Stefan waiting for her. She tells him she hated the fight, he agrees it felt too real. They both know Caroline was listening and assumed Katherine got to her. He doesn't plan to tell Damon it was a fake fight.
Stefan's sure he's not why Katherine's there.
He says she's not capable of love.
Flash back to the past, the Salvatore brothers lying dead and George Lockwood finding Katherine. He brought her a carriage, she lives up to her part of the deal and gives him the moonstone. She goes to leave but first goes back to Stefan and tells him she loves him and they'll be together again. She kisses him.