The Vampire Diaries.

Based on season Three of TVD...

Caroline throws Elena and Ellie a party at the Salvatore boarding house for their 18th. Klaus and Stefan learn Damon has been following them, so Stefan returns home and kills Damon's girlfriend, Andie, as a warning.

In an attempt to bring Stefan back, Ellie and Alaric go to Tennessee in search of Stefan and Klaus. Tyler learns that his mom has taken Caroline. Stefan and Klaus visit Chicago, where Stefan gets flashbacks that he was friends with Klaus and that he was in love with his sister, Rebekah. Katherine calls Damon and tells him Stefan and Klaus are in Chicago. Tyler and Elena enlisted Sheriff Forbes.

Klaus and Stefan visit a witch, trying to figure out why Klaus's attempts at making hybrids continue to fail. The witch tortures Stefan and finds out that the doppelgänger is still alive. Katherine shows up and kills the witch to help Stefan protect his one true love. Klaus brings Stefan back to Mystic Falls to see what Stefan's hiding.

The seniors hold a prank night at school, and Klaus shows up and finds Ellie's still alive. Klaus feeds Tyler his blood. Klaus then realised he needed Ellie's blood to successfully create hybrids. Damon and Katherine go on a road trip to try and find Mikael. Klaus compels a nurse to drain Ellie of her blood, but Damon shows up and tells Klaus Mikael is coming to town.

Lexi appeared to Ellie, and they tried to get Stefan's humanity back before Ellie gave up on him. Bonnie is reunited with her grandmother. Jeremy can now touch Anna, and Ellie sees them kissing. Rebekah reveals to Ellie and Elena how they became vampires. Stefan enlists Bonnie's help in hiding the coffins he and Ellie took from Klaus. Klaus has one of his hybrids hit Jeremy with a car. However, Alaric is hit instead. It is revealed that it isn't working the same way, and it does not fully heal him.

It's Caroline's 18th, Matt, Ellie, Elena, and Bonnie surprise her with a party to send off her human self. Jeremy leaves.