Katerina Petrova gives birth to a little girl and immediately has the baby taken away from her by her father, who says she has brought shame on her family.
In present day, Elena visits the boys. Rose is there. She tells them about Klaus, one of the original vampires, Elijah is his foot soldier. They're after Elena. Rose assures them Klaus won't quit until he gets what he wants. Elena excuses herself to go to school.
Arriving at school Jeremy casually asks Bonnie if she wants to play pool later. A new guy introduces himself as Luka to both of them and Bonnie seems to like what she sees.
Trudging through the woods, Elena is lugging a giant suitcase and telling Caroline to cover for her, especially with Stefan.
Elena goes down into the tomb, hoping to ask Katherine about Klaus. Caroline opens the giant stone tomb door. Katherine is weak and emaciated inside.
Elena urges Caroline to leave, saying she'll be fine as long as she doesn't cross into the tomb where Katherine is held by the spell.
She asks about Klaus. She brought the Petrova family history and a bottle of blood. She pours some in a cup and scoots it across the threshold for Katherine.
The story of her and Klaus goes back to England in 1492, after she was thrown out of Bulgaria by her family. They disowned her for having a baby out of wedlock. She met Klaus the nobleman but ran when she learned what he was.
Cut to Katherine running through the woods away from Elijah. One of the group diverts him away. Then he finds Katherine -- we see that it's Trevor, the vampire Elijah beheaded - and tells her to run.
Klaus wanted her blood.
Damon finds Rose crying over Trevor. He asks her how to find Klaus. She found Elijah through Slater in Richmond.
At school, Caroline stops Stefan on his way to check on Elena, who he thinks went home sick. She tells him she told Tyler she was a vampire.
Elena feds Katherine more blood and she explains that the curse was bound by Petrova blood. The doppelganger was created as a way to undo the spell.
Cut to Katherine running through the woods to a cabin. She finds an old woman and Rose inside. She shows her the moonstone. Rose doesn't want to go against Klaus and tells her she's bringing her back to him.
Rose and Damon arrive at an office building. He threatens her, warning her not to double cross him. She turns him around, reminding him she's older and stronger. But she says he can trust her.
Slater recognizes Damon, and knows about the tomb under the church.
Katherine continues her story...
Rose checks on Katherine, who has hurt herself, saying she'd rather die than be sacrificed. Rose tries to feed her some blood. Trevor comes back, saying he loves Katherine and they can run from Klaus. They see that Katherine has hung herself.
Katherine explains to Elena that Klaus needed a human sacrifice so she turned. She draws some of her own blood and offers it to Elena, taunting her.
Back in 1492, Rose realizes that Katherine used Trevor to escape and her to turn. She knows Klaus will be after them.
Katherine is unmoved when Elena points out she ruined their lives.
Caroline and Stefan eat at the grill. He says she reminds him of his best friend Lexie. She says Tyler is freaking out about the upcoming full moon.
At another table in the Grill, Luka sees Bonnie and introduces her to his dad, Dr. Jonas Martin. She agrees to join them, waiting for Jeremy.
They moved from Louisiana. Jonas says he knew some Bennetts from his residency and asks if she has family in Salem.
Jeremy arrives. She says good bye, touching Luka on the shoulder and feeling something.
Slater says the way to get in touch with Klaus was Craigslist, but that only leads to Elijah, who they think is dead.
Outside, a man in a black suit scoops coins from a guitar players tip case. It's Elijah. He's standing outside the coffee shop Rose and Damon are in.
Bonnie plays some very bad pool with Jeremy. Luka joins them.
Stefan figures out Caroline is stalling and asks where Elena is. She refuses to tell him. He leaves.
Back in the tomb, Elena guesses that Katherine was planning to turn her over to Klaus to gain her freedom.
Elena puts together what else is needed to break the spell: a werewolf and a witch. Also, Katherine tells her, she needs a vampire: Caroline.
Back in the coffee shop, Slater explains that if a werewolf breaks the curse first, vampires are stuck and vice versa.
Elijah listens outside. Then he throws the coins through the tempered glass. It shatters and Rose and Slater are burned by the sun.
Damon covers her with a jacket and helps her out. She's sure Klaus was behind it.
Bonnie watches Jeremy play pool, Luka joins her, apologizing for his dad asking about the Bennetts of Salem. He says he doesn't like anyone to know, but they were both worried she'd out them. They're warlocks.
In the tomb, Elena is ready to go and Stefan finds her. He tells her Katherine is a liar.
She finishes her story...
Katherine returns to her house to find her family slaughtered.
She tells Stefan that Klaus will have vengeance. She says Elena is doomed, unless they have the moonstone -- which she's holding.
She says she'll be safe in her tomb when Klaus comes to town.
At the house, Rose apologizes to Damon. They share a drink. Rose says Damon is right to fight the way he feels about Elena because if they're going to survive, they can't care. She says it's time to turn the switch off on their emotions.
Which apparently they do by making out.
Jeremy plays pool and sees Bonnie talking to Luka, hitting it off. He seems to know he missed his shot. He leaves.
Stefan walks Elena home, she tells him Bonnie, Tyler and Caroline are in danger. She says it's not because he came into town, it's because of her. He holds her as she cries.
In her tomb, Katherine reads her family history. She sees an old drawing of her parents.
Back at the house, half naked, Rose tells Damon there's no emotional switch to turn off. Her phone rings. It's Slater. He tells her they need the moonstone to destroy the curse, and a witch. He wishes her luck and gets off the phone.
Elijah compliments him for his performance. He was able to compel Slater because he's an original. He hands Slater a stake to drive through his own heart. He does it.
We see that Elijah is not alone: Dr. Jonas Martin is there. Elijah says Slater delivered his message and it won't be long now.