Elena wakes to find herself in transition, and struggles with the decision to feed and become a vampire, or die. Meanwhile, Bonnie attempts to find a way to save her human soul, with Jeremy's help, and revert Elena to human. Stefan and Damon find themselves at odds with each other over Elena's situation. In the meantime, Pastor Young takes over the Founders Council, excommunicating Sheriff Forbes and Mayor Carol Lockwood. He is executing his plan to rid Mystic Falls once and for all of vampires by abducting anyone he knows/suspects to be a vampire, including Elena, who he realizes is turning. Caroline and Rebekah find themselves among the abducted, but Klaus, still possessing Tyler's body, rescues Caroline, but leaves Rebekah. Thankful Tyler is alive, Caroline kisses Tyler and suggests they have "hot vampire-hybrid sex," but she discovers he is possessed by Klaus just in time. Klaus becomes anxious to get his own body back, having grown tired of using Tyler's. Upon finding his body wasn't completely destroyed, he forces Bonnie to tap into dark magic to make the switch by threatening to kill Tyler. As a result, angry spirits punish the ghost of Grams, who had unsuccessfully warned Bonnie against using dark magic. Damon and a guilt ridden Matt find where the captured vampires are being kept, and Damon fights the outside guards. Stefan notices Elena is dying, so, with Rebekah's help, he kills one of the guards by breaking his skull over the cage's bars, allowing Elena to feed. Using her newfound vampire strength, her and Stefan escape. Fearing retaliation from the vampires, Pastor Young kills himself, along with the remaining members of the council, by blowing up his house. Stefan gives Elena a daylight ring Bonnie made her. Klaus, now in his own body, disowns Rebekah, and a hurt Rebekah destroys the bags of Elena's blood, making it impossible for Klaus to make more hybrids.
The Pastor's daughter, and old friend of the Gilberts, April Young (Grace Phipps), returns to town following her father's death. Meanwhile, a vampire hunter, Connor Jordon, is investigating the supernatural population of Mystic Falls under the ruse of investigating the explosion that killed the Council. Using gloves made of vervain, Connor discovers Tyler has vampire blood in him and immediately shoots him, but Tyler escapes while Connor is reloading. Jeremy meets Connor at the Mystic Grill and notices a tattoo only he can see. Despite Stefan's best efforts, Elena is having trouble keeping animal blood down, and turns to Damon for help. Insisting she needs blood from the vein, he allows Elena to drink from him; however, she is unable to keep down Damon's blood as well. At the memorial held for the victims of the explosion, Connor kidnaps, stabs, and brings April to the second floor of the church, trying to use her blood to draw out any vampires in the church. Matt allows Elena, who is losing control because of the blood, to feed on him inconspicuously. Since Tyler is a hybrid, he reveals himself and allows Connor to shoot him to protect his vampire friends, who escape during the panic started by the public shooting. When Elena and Caroline go to rescue April, Elena begins to lose control and tries to attack April. However, Caroline stops her, and Elena pulls it together enough to heal and compel April. Damon tries to fight Connor in the parking lot, but is overpowered. Stefan comes to his aid and Connor makes a run for it. However, Stefan is upset that Damon blood-shared with Elena and punches him. The episode ends with Connor finding a note written by the Pastor about a "greater evil," and Elena and her friends having a private memorial for everyone they have lost.
In the hospital, Connor breaks in and steals Tyler's werewolf venom. The gang returns to school, and Matt allows Elena to feed on him in their old make-out spot. On their way inside, they discover that a curfew has been put into effect due to the shooting at the church. Stefan tries to show Elena that being a vampire can be fun, but Rebekah also returns to school and begins to torment Elena by bringing up Alaric and tempting her with blood. Connor comes to the school and tells Jeremy that the reason he can see Connor's tattoo is because he is a potential hunter. Connor uses force to get Matt to confess who is feeding off him, but he lies and says it's Rebekah. Klaus returns to protect his hybrids from Connor, and takes residence in the Lockwood house. Haley, a female werewolf who helped Tyler break Klaus' sire-bond, arrives, and Klaus suspects they had a less-than-platonic relationship in the Appalachia's. Meanwhile, Rebekah decides to throw an anti-curfew party at her house, and Elena and Stefan decide to attend. At the party, Rebekah steals Elena's ring and nearly destroys it. Elena, who had previously convinced Damon to give her the White Oak Stake, plans to stake Rebekah, but Stefan intervenes and convinces her to come with him to blow off steam (not before Elena makes a grand exit from the party by doing an unassisted keg stand). When Stefan and Elena return, she becomes sick due to the keg being spiked with werewolf venom. Meanwhile, Damon and Klaus, who have temporarily teamed up, trap Connor in the hospital storage room via rigged explosives. Connor attempts to stake Klaus, but Klaus disarms him. Upon seeing a familiar symbol on the stake, Klaus realizes Connor is one of The Five. When Connor triggers the explosives, Klaus saves him and holds him captive to pump him for information. Klaus, acting out of character, gives Elena his blood and heals her, saying he may have a use for her after all. At the end of the episode, April stays behind at Rebekah's, who is also recovering from the werewolf venom, to help clean up and befriends her.
Klaus and Rebekah realize Connor is one of "The Five," a clan of legendary vampire hunters that existed 900 years before. Rebekah, who had fallen in love with their leader, Alexander, discovered they possessed an "Ultimate Weapon" against vampires, and that the key to finding it was using their swords to decode their tattoos (hunter's mark). However, Alexander discovered Rebekah was a vampire, and used a dagger and her and her brothers. Klaus, unaffected by the dagger, killed Alexander and his fellow hunters, and un-daggered his family. Meanwhile, Bonnie, Elena, and Damon head to Whitmore College, where they meet Professor Shane, who appears to be a believer in the supernatural, and takes a liking to Bonnie. At a party being thrown on campus, Damon teaches Elena how to feed properly. At the party, Elena becomes intoxicated by the blood and dances with Damon. However, she is snapped out of her trance by a scared Bonnie. Elena becomes scared she might become like Damon, much to his offense. Stefan learns the "Ultimate Weapon" of The Five is a possible cure for vampirism, and tricks Rebekah into revealing she buried Alexander with his sword. Klaus has Jeremy draw a picture of the tattoo, but finds it's incomplete, and that it only continues to form as long as Connor kills vampires. Meanwhile, Connor escapes Klaus by killing one of his hybrids, and leaves to find the one who sent him to Mystic Falls in the first place - Professor Shane. Klaus once again daggers Rebekah.
After being told by Shane that the truth about his tattoo will be revealed, Connor returns to Mystic Falls, agreeing to kill humans if necessary. Stefan and Klaus team up once again to stop Connor, but Klaus leaves to find Alexander's sword. Connor takes Jeremy, Matt and April hostage. April who doesn't know of vampires yet, and so thinks Connor is delusional and is naturally scared of him. Stefan and Damon argue on the best course of action. Damon is knocked unconscious and the situation turns violent when one of Klaus's minions is sent to stand up to Connor. Meanwhile, Shane is trying to get Bonnie to get over her guilt via hypnosis, which at first appears not to work when he tries to get her to light a single candle, but when Bonnie opens her eyes she sees she lit every candle in the room. Jeremy tries to talk to Connor, who explains a friend of his was once turned into a vampire but he had to put that friend down, and then the tattoo began to appear. Elena breaks in and attacks Connor, but he is taken away by Stefan. Damon catches up to them and confronts Stefan on why he doesn't kill Connor and he explains Connor is the key to a cure. When Connor makes a run for it, the brothers witness him being killed by Elena, much to her guilt.
We All Go a Little Mad Sometimes
Elena is hallucinating about the death of Connor, which is slowly driving her mad. Klaus informs the Salvatore brothers that Elena needs to be locked away, because eventually she will try to kill herself. After stealing her away from the brothers, he explains that due to killing the original five hunters, he experienced the same thing and there is no cure. Meanwhile, Shane is hosting an exhibition at the school with Bonnie's help. Damon and Bonnie turn to him for answers. He tells them that Elena's hallucinations are due to a witch's curse and the only cure is for a potential hunter to make a first kill and pass along the last hunter's powers. Jeremy has discovered the beginnings of the mark on him. Stefan goes to break Elena out only to have her attack him and escape. She goes to the bridge where she died and the hunter, Katherine, and her mother convince her to take her own life. She drops her daylight ring into the water. Stefan sends Damon to bring her back. Klaus provides Jeremy with one of his hybrids to kill to complete his transition to a hunter and break the curse. The curse is broken just as dawn comes, and Damon saves Elena by throwing them both in the river. He tells Elena that Stefan had been lying to them, but it was all for her. Stefan and Elena sit on the front steps and talk. Elena admits that as a vampire, her feelings for Damon have been magnified, and Stefan tells her he can't do this anymore so they mutually decide to split up.
My Brother's Keeper
The Miss Mystic Falls pageant is back, and Elena and Caroline help April find something to wear. Meanwhile, Caroline calls Stefan and Stefan tells Caroline about Elena's feelings for Damon, which Caroline objects to. Klaus shows up shortly afterwards, questioning Stefan's trust in him. Damon and Stefan's relationship is even more strained, but they continue their search for the cure to vampirism for Elena's sake. Caroline and Elena are suspicious of Shane, who Damon decides to confront. Ever since awakening as a hunter, Jeremy has been having nightmares in which he kills Elena. Stefan uses criminals to create vampires for Jeremy to use to complete his tattoo. Hayley and Tyler work to break the sire bond of Klaus's hybrids. Caroline is stressed by a favor she owes Klaus- a date. Klaus manipulates her into feeling jealous of Hayley and Tyler's friendship, while also charming her. She asks if he ever wanted to be human again. Jeremy's hunter instinct- a hatred of vampires- develops to the point that he attacks Stefan. Damon asks why Shane showed up in Mystic Falls in the first place causing Shane to reveal that he is a vampire. Jeremy arrives at the pageant and attacks Elena, nearly killing her. She is rescued by Stefan and Matt. Stefan reveals to Elena he provided vampires for Jeremy to kill, to which she replies that she doesn't want her humanity back if it costs her brother his. Matt moves into her house and Elena decides to stay in the Salvatore House. Stefan then decides to leave, unable to stay in the same house as Elena. It is eventually revealed that Shane and Hayley are working together to break the sire bond with Klaus's hybrids. Later, Elena has a talk with Damon, which leads to a dance between the two and sex afterwards, all while Caroline and Stefan figure out that Elena is sired to Damon.
We'll Always Have Bourbon Street
After Elena and Damon wake up and continue where they left off the night before, Stefan arrives to the Salvatore house and aproaches Damon with the suspicion that Elena is sired to him. Stefan advises Damon to ask Elena to try and drink from a blood bag again and see if she can keep it down, since he believes the only reason she can only drink straight from the vein is because Damon told her to. He does and sees that she can now keep the blood down. Damon decides to help Stefan investigate the sire bond in New Orleans, hoping to find a former flame of Damon's who was also sired to him. While the Salvatore brothers are out of town, Elena, Caroline and Bonnie share a girls