A pregnant Katarina Petrova goes into labor.
In the present, dead Katherine gets shocked in a hospital to restart her heart.
Katarina gives birth to a girl and her mother won't even let her hold her before his father takes her away.
At the hospital, Stefan tells Nadia that Katherine a heart attack. The doctors are able to start her heart again but she's dying and isn't expected to last the day. Stefan compelled the doctors to let them take her home.
Backat Whitmore, Caroline and Bonnie bring Elena a "break up breakfast." Caroline does not even try to pretend she's not happy about the break-up, she even memorized what Damon said to her.
Matt and Jeremy find Damon passed out at the Grille. He wakes up and starts drinking again.
Stefan calls them both with the Katherine news.
Back at the house, Damon pours Matt and Jeremy shots for all the horrible things Katherine has done to them through the years. The girls arrive.
Damon waits to see how Elena will react. She takes a shot. "If anybody is drinking to Katherine's last days, it's me. She impersonated me, repeatedly. She made Aunt Jenna stab herself in the stomach and she cut off Uncle John's fingers."
They all pile on. Bonnie Gram's died tried to close a tomb Katherine wasn't in. Tyler's werewolf curse was triggered because of her. Miles followed her to Mystic Falls and because of that, they lost Jenna and Alaric. Matt goes for more booze.
Upstairs, Stefan sits with Katherine. She worries she looks wrinkled and tells him if she starts to sag, anywhere, he should jab a knife into her carotid artery.
He's being nice because she's dying.
Down in the cellar, Matt is surprised to see Nadia. She knocks him out cold.
Stefan comes downstairs to tell everyone they're being sensitive, but Damon warns him not to let the fact she's an Elena lookalike could the fact she's a manipulative psycho.
Stefan mentions her seducing both him and Damon, turning them into vampires and starting a war with the town that got them killed. But he goes on to say that before that she was just a frightened girl shunned by her family, and she became a survivor, so that's what he'll drink to.
Damon mocks Stefan for being so easy on her after one night of passion. It's news to Elena. Nadia arrives, she's also news to Elena.
Nadia explains she has found a way to save her mother. Damon forbids anyone to help, which Nadia expected, which is why she buried Matt in the safe somewhere on the property, without his ring.
Elena and Stefan volunteer to help, just as Nadia expected. She explains she needs a Traveler to teach Katherine how to transfer to another body. Elena doesn't understand why she wants to save Katherine given that she killed Nadia's boyfriend.
Stefan defends her and he waits for Elena to lay into him for sleeping with Katherine.
Nadia takes them to a boarded up house and tells them who she plans to transfer Katherine to: Herself.
Back at the house, Caroline, Bonnie and Jeremy search for signs of digging. Caroline is ready to talk about Stefan sleeping with Katherine, but Jeremy dismisses it, saying they've all had their fair share of bad choices.
"No offense taken," Bonnie says, and Caroline figures out they slept together. Caroline is disappointed to be the only one not having "scandalous sex."
On her death bed, Katherine remembers coming home in Bulgaria in 1492 to see her family slaughtered. Then Damon walks in to the Bulgarian cottage to rub it in, reminding her that Klaus only killed them because he was going to sacrifice her and she ran, so her family's death is her fault.
Back in the bedroom, Damon picks up a pillow to smother an unconscious Katherine. But Liz Forbes comes in and stops him.
"Every awful thing I've done is linked to her. She taught me how to kill, how to enjoy it. She ruined me and I can't take any of that back," he says.
"Look at how much control she still has over you, Damon. Prove her wrong," Caroline says.
Caroline is walking through the woods looking for Matt when she stops in her tracks. It's Klaus.
In the abandoned house, Mia, the Traveler that Nadia paid off joins them. Nadia says the price was them, dopplegangers. Then both Nadia and Mia run, locking Stefan and Elena in the house. Dozens of Travelers come inside and surround the house, chanting and rendering their daylight rings useless.
In the woods, Caroline tries to ignore Klaus. Damon told him Katherine, whom he's been hunting for 500 years, is on her death bed. He knows Caroline and Tyler broke up, but tells her Tyler is fine, he sent him off with "little more than a bruised ego." Caroline explains she told Tyler to chose between her and his revenge fantasy against Klaus, and he chose wrong.
In Katherine's room, Liz brings sedatives from the hospital, but Katherine doesn't want them because they make her weak and let Damon into her head. Katherine mocks him for breaking up with Elena and Damon grabs a syringe and injects her anyway, knocking her out.
Mystic Falls, 1864
Katherine in on the road in her carriage heading to the Lockwood Plantation with Emily. She sees Stefan on the side of the road with a broken down carriage and takes a liking to him immediately.
Damon is surprised to learn how they really met. Katherine thinks it seemed like fate, bringing the two doppplegangers together just like the prophesy said.
Back in the abandoned house, Elena apologizes to Stefan for judging him. They are huddled in a corner to escape the sun's rays streaming through the dilapidated house. The Travelers continue chanting in the room and one approaches with two buckets. He slices both Elena and Stefan's wrists to drain their blood, but Elena realizes they aren't healing.
Klaus finds Caroline again, and asks if she'd offer him the same choice, if he gave up his revenge fantasy against Katherine. Caroline is focused on finding Matt, but he assures her he's got it covered, he heard Matt's screams and "he'll be quite happy with his rescuer."
Matt's safe opens in the woods and he gets out to see Rebekah standing there.
On her death bed, Damon toys with Katherine. First she sees Jenna returning with a knife, which she uses to stab Katherine. Then John shows up with his own knife to hack off her fingers.
Then Elijah appears to put a stop to it. She's happy and touched to see him, but then he turns into Damon, who informs her it wasn't real and no one is coming to see her because no one cares.
But Nadia walks up behind Damon and snaps his neck, saying she cares. Mia the Traveler is with her.
Back in the house, Stefan tells Elena that Katherine helped him with the Silas aftermath, but gives her permission to hate Katherine anyway. He knows he should hate Katherine, but he doesn't.
"Damon keeps pushing you away because he hates himself, who he is, what he's done. Just remember that you never gave up on me, so don't give up on him. Don't let him give up on you either, OK?" Stefan says.
The Travelers stop chanting and Stefan and Elena heal. The sunlight doesn't burn them anymore. "So that's all you wanted was a bucket of our blood?" Elena says. They walk out of the house.
Back at Katherine's bedside, Nadia is ready to become her mother's passenger, but Katherine isn't. She tells Nadia that letting her father take Nadia from her was the biggest regret her life and she vowed never to give up so easily again. She spent the next 500 years fighting for everything and lived a full life. She tells Nadia it's her turn to live.
Damon wakes up on the floor but stays still and listens as Katherine tells Nadia that she's been selfish her whole life and just wants to do the right thing for once. She asks Nadia to let her go.
Nadia is upset, and refuses to watch her mother die. She leaves.
Katherine injects herself with another sedative.
In the woods, Klaus tells Caroline he did come to gloat over Katherine's corpse-to-be, but he'll leave in exchange for Caroline's confession -- about him.
"As soon as we're done here, I'm going to walk away and I'm never coming back. You'll never again have to look me in the eye and cover our connection with hostility and revulsion. You'll never have to loathe the darkest parts of yourself that care for me, in spite of all I've done. I will be gone, and you will be free. I just want you to be honest with me," Klaus says.
Caroline tells him she's in college and has a plan for her life that doesn't involve him, but if he promises to leave and never come back, she will be honest with him.
She smiles, then steps close and kisses him. They tear each other's clothes off in the woods.
Stefan comes up to Katherine's room to see Damon waking up from the floor. "In a shocking twist, Katherine's daughter's a psychopath," Damon explains.
Stefan's about to chide Damon when he confesses to messing with Katherine's mind. "I know, I know. It's been a rough couple of days, I needed an outlet," Damon says.
He leaves Stefan with Katherine.
He tells her he came to say good-bye. She closes her eyes and sees herself back in the cottage with her murdered family. Stefan is there and she tells him it was the worst day of her life and Damon said it was all her fault.
Stefan urges her to open her mind to him. Stefan makes the images of her dead family disappear as he tells her she was just a 17 year old girl, and none of it was her fault. "You deserve to feel at peace," he says.
Katherine hears a baby cry and turns around to see Nadia as a baby in a crib. It's the last image that she sees.
Stefan kisses her good-bye. When Elena comes in, he tells her Katherine isn't quite gone, but won't wake up again.
Outside, sharing a drink, Stefan tells Damon that Katherine helped pull him out of a dark place. Stefan tells him to fix whatever is going on with him and Elena. Damon says he can't live without her, but he doesn't think he's any better than Katherine and Elena will be better off without him. He's trying to be selfless.
Stefan gives him a look. Damon tells him when he gets Elena back and the whole universe freaks out for keeping the dopplegangers apart, Stefan should remember he's the one who talked Damon out of doing the right thing for all mankind.
Caroline comes back to the house with leaves in her hair. She says she got lost.
Matt asks Bonnie about being the anchor. He wants to know if she sees Vicki, who appears as he asks. Vicki tells him to tell Matt she watches over him, and he should stop hanging around with Rebekah.
Then Tyler walks in. "Rebekah says to tell you I'm her parting gift," Tyler says. He and Matt hug.
Everyone gathers in front of the fire, going through bourbon. Jeremy hears Alaric.
"Where the hell have you been? I thought you bailed on us to go find peace or something," Jeremy says.
"Do you honestly think I'd leave Damon in charge and never look back?" Alaric says.
Jeremy translates to Damon: "He says you're a dick."
Suddenly, Bonnie sees Katherine's spirit. But only for a second.
Katherine startles back alive in bed, with Elena sitting next to her. Katherine says she has unfinished business.
Elena says she has a whole speech, but she skips to the end. "I forgive you. You weren't born evil, life made you that way," Elena says.
Katherine asks Elena to give her the last sedative. "If anyone's going to plunge a needle in me one last time, it might as well be you. Symmetry and all that," Katherine says.
Elena takes the needle and Katherine thanks her for her forgiveness. Elena plunges the sedative in, but before she takes her last breath, Katherine grabs Elena and recites the Traveler's incantation.
Katherine transfers into Elena. A phone rings nearby, with Mia the Traveler calling to activate Katherine. Mia hands the phone to Nadia. "Talk to me, did it work?" Nadia asks.
Katherine, now in Elena's body, checks her corpse's pulse and goes to assess herself.
Katherine checks herself out and gets ready to be Elena.