Set after 3x22. Elena has been turned, and now faces new challanges as a vampire. Tensions between the Salvatore brothers reemerge as Stefan tries to make sense of the new Elena, and Bonnie must try set aside her dislike of vampires for her friend's sake. Amid all of this, Katherine returns, and the stage is set for revealing the Petrova bloodline's biggest secret.

Our masters warned us against feelings that would lead to the Dark Side. Hate. Anger. Vengeance. They want control. They want us to have control. But he killed them, he killed them all. We were betrayed. We were all but annihilated. And they tell us now that to rebuild, we will need control more than ever. Perhaps this time they ask too much.