In an attempt to continue the breed of hybrids, Klaus and Stefan start hunting for one of the oldest werewolves in order to turn them into vampires. Klaus and Stefan and discover that Damon has been tracking them down. Stefan gives Damon a warning and kills Andie, his half compelled girlfriend, by compelling her to fall off a cliff. Caroline holds a party for Elena’s 18th birthday. Elena finds out about Damon’s plans to find Stefan and is upset that he had not told her about them. Caroline and Tyler end up spending the night together at the Lockwood’s house and she is caught sneaking out in the morning. Mrs. Lockwood’s suspicions about Caroline are confirmed and she shoots her several times with vervain. Stefan learns that Klaus might be running away from someone who is hunting him. When Gloria finds out that Stefan’s girlfriend, Elena, is still alive, she tortures him. Stefan is eventually rescued by Katherine.

Damon kills Alaric who later comes back to life. Caroline saves the life of her father by making him drink her blood. Mikael is revealed t be the person that Klaus and Stefan are running away from. However, when Stefan mentions Mikael’s name, he is knocked out by Klaus. Bonnie is fooled by Katherine who has stolen Elena’s necklace. Klaus threatens to kill Tyler is she does not find a way of creating hybrids in the next twenty minutes. Klaus also makes Stefan to feed on Elena. It is later discovered that Elena’s blood is what is needed to create more hybrids. As a result of Elena’s blood, Tyler becomes the first hybrid to be sired by Klaus. Elena is later rescued by Damon who promises never to leave her again. Mikael rises from the dead.