After assigning tasks to each of her friends, Caroline attempts to deal with her current situation as reality begins to set in around her. While spending the day with Caroline, Elena grows concerned when she starts noticing a strange change in her behavior. Meanwhile, Alaric becomes wary when Kai, who has begun experiencing unexpected consequences from the merge, turns to Jo, desperate for her help. Elsewhere, while Bonnie finds herself in an unfamiliar situation, Matt and Tyler contemplate a major life change. And when Damon offers Caroline advice on how to cope with everything going on around her, it forces him to revisit painful memories involving his own mother.

In the aftermath of his brother's fateful decision, Stefan awakens to find himself thrown into a life or death situation with only his basic instincts to rely on. With time working against him, he sets off on a journey of survival while forced to confront a lifetime of irreversible damage Damon has done to their relationship.

Meanwhile, desperate to save his brother, Damon follows an unusual lead he has come across, while Matt sends Valerie to Dallas to enlist Alaric's help in the search for Stefan. Finally, when Rayna discovers the emergence of a new threat, she sets off on her own mission to find Stefan before the others do.

With the fate of Mystic Falls at stake, Stefan and Damon must fight their greatest enemy for one last battle.