Stefan takes drastic measures to find out the real reason Katherine has returned to Mystic Falls, and is shocked when she reveals new secrets about what really happened in 1864. Damon tries a new tactic to resolve his issues with Mason,.... but it proves costly. Tyler pushes Mason to tell him the truth about the Lockwoods. Finally, when Katherine delivers an ultimatum, Stefan and Elena are left with very few options.

On the first day of their senior year, Elena, Caroline, Bonnie and Matt are still reeling from recent events, while Tyler seems to be enjoying everything a little too much. Damon is annoyed by a new houseguest, and everyone is surprised by the arrival of a new student in Alaric's history class. Matt asks Bonnie for help when he realizes he made a serious mistake. Meanwhile, Stefan continues to carry out his latest assignment from Klaus.

Elena tries to cope with the extreme highs and lows that are part of becoming a vampire, and Stefan and Damon almost come to blows while arguing about what is best for her. Damon decides to help Elena in his own way and asks her not to tell Stefan. A stranger, Connor Jordan, arrives in town and begins questioning Sheriff Forbes and Mayor Lockwood. Connor’s actions quickly convince Stefan that they are dealing with a dangerous vampire hunter. Jeremy and Matt are surprised to see a girl they used to know, April, has returned to town and is enrolling at Mystic Falls High. At a town gathering, Elena comes close to losing control until Caroline steps in to help her. Finally, Damon confides his feelings to an unexpected friend.

Tasked with finding a mysterious artifact, Damon’s latest mission takes him to Texas where a violent run-in with Peter Maxwell leads to a surprising revelation. Meanwhile, after gaining the upper hand in their fight to save Damon and Enzo, Stefan and Alaric team up and uncover the origins of the mysterious force they’re up against. Finally, Matt returns to the fray after his past and present collide in an unexpected way.