Klaus (Nicklaus) mikaelson is one of the original vampires along with his siblings Elijah, Rebekah, Finn, and Kol. Unfortunately, they didn't share the same father. Towards the end of season two, it's revealed that Klaus is from another bloodline, a werewolf bloodline. Being born with a werewolf gene, when he was turned into a vampire he became the original hybrid (the best of both species and none of their weaknesses). The original witch cursed him to never realize his full potential keeping his werewolf side locked within him. Throughout the season, Klaus is mentioned as a boogeyman type of character with a vendetta to settle with Katherine. It turns out that in order for him to break his cure, Klaus needed a Petrova doppelganger. Katherine learned this and turned before he had the chance to kill her. When he finds out there's another doppelganger, Elena, Klaus makes his way to Mystic Falls to claim her.Without regard for anyone, Klaus proceeds to turn Jenna, Elena's aunt, and use her for the vampire in the spell, killing her shortly after she transformed. While Stefan watched, the elder vampire drained Elena, killing her and breaking the curse for good. What Klaus didn't know, was Elijah had agreed to help kill him before his own transformation was complete. Before he died however, Klaus told his brother he didn't kill their family and spread their bodies in the ocean, that if Elijah spared his life, he'd take him to them. Praying on his brother's need to find their family, Klaus gets to complete his transformation, becoming impossible to kill. As per his word, Klaus takes Elijah to where he had hidden the family after plunging the silver dagger through his brother's heart.Stefan seeks out the newly formed hybrid after the witches tell Bonnie he has the only cure to save Damon (the hybrid's blood). Klaus forces Stefan to agree to go on a ripping rampage, to be at his side for the next ten years. Stefan reluctantly agrees and the two set off. Slowly we learn that Klaus's main interest was siring new hybrids like himself, the perfect race of monsters, but all of them died before they can transform. He finds the help of a witch he knew in the twenties when he originally had met Stefan. On her advice, Klaus wakes his sister Rebecca from the 'death coma' he had put her in shortly after he compelled Stefan to forget meeting them the first time. When he learns the necklace she wore was the key they need, he asks the witch to locate it. The necklace ends up being the same Stefan had given Elena and in locating it, Klaus finds out the doppelganger is alive and that's why the hybrids aren't turning.The group make their way back to Mystic Falls when Klaus learns that not only is Elena alive, but Stefan has been asking probing questions. While there, Klaus threatens Elena's friends, going so far as to turn Tyler in order to persuade their compliance in finding a cure. While Rebecca tends to the turning werewolf, Klaus sees that Stefan's love for Elena is too strong for him to ever have complete control over him. Against his wishes, Klaus compels Stefan to forget his humanity and obey everything he says. Shortly after, Klaus learns the doppelganger's blood was the key to turning the hybrids and it had been the original witch's fail safe should he break the curse. Had she died in the ceremony like she was meant to, he never would have been able to use her blood to aid the transformations.With Stefan's help and Rebecca in toe, Klaus takes Elena to a hospital and begins to drain her of a few pints of blood, but before he can collect, Damon gives him distressing news. Mikael, a vampire-vampire hunter that has been searching for Klaus for the better part of a century has been found and awakened. Distressed, Klaus commands Stefan to guard Elena and left Rebecca behind to watch over Tyler. As of now, no one knows where he is. Show less «