When a confused and desperate Caroline (Candice Accola) leaves the hospital and joins her friends at the Mystic Falls Carnival, Damon (Ian Somerhalder) wants to take immediate action, but Stefan (Paul Wesley) and Elena (Nina Dobrev) come to Caroline's defense. Matt (Zach Roerig) is completely mystified by Caroline's behavior, but still tries to tell her about his feelings for her. Damon has suspicions about Tyler's Uncle Mason (guest star Taylor Kinney) and uses Tyler's (Michael Trevino) volatile personality in an attempt to get Mason to reveal his secret. Upset with everything going on around her, Bonnie (Katerina Graham) takes her anger out on Damon.