Months after Damon and Enzo mysteriously vanished from the Armory vault, Stefan tirelessly pushes forward with their search, while Bonnie struggles holding onto hope that they will be found. Meanwhile, a dangerous encounter with an unexpected visitor leaves Caroline and Alaric fearing that someone - or something - may be targeting their family. Finally, after following some mysterious clues, Stefan realizes that whatever has a hold of his brother may have a more damaging grip over him than he could have ever imagined.