As Mystic Falls gets ready for a festival to celebrate the passing of a comet, Vicki continues to recover in the hospital following Damon's attack. Stefan heads to the hospital to try to use his abilities to make Vicki forget who attacked her, but his efforts are cut short by Matt. Meanwhile, at a parent/teacher conference Mr. Tanner tells Aunt Jenna that Jeremy is in trouble and needs immediate intervention.

As Elena tries to ignore Bonnie's warnings about Stefan, Tyler tries to embarrass Stefan by throwing a ball at him. However, his effortless catch and football skills impress everyone, leading Mr. Tanner to let him join the football team. Meanwhile, Elena invites Stefan and Bonnie to dinner in order to try to get the two to know each other, but the night ends up backfiring. Finally, the town is shocked by an act of violence.

Elena asks Stefan to escort her to the town's annual Founder's Party. Vicki gets Tyler to ask her to the party, then accuses him of trying to hide their relationship from his family. Zach reveals a useful family secret to Stefan. At the party, Damon tells Elena a story about the Salvatore family's past, leaving Elena with questions that Stefan refuses to answer. Finally, Stefan takes action to get Damon out of his life for good.

Stefan takes action to protect Elena. Stefan is hopeful that his plan to get rid of Damon is working. Elena and Jenna are concerned about Jeremy’s relationship with Vicki. Stefan decides to reveal parts of his past to Elena. At a fund-raising car wash, Bonnie is surprised by abilities she didn’t know she possessed, and seeks advice from her grandmother. Finally, Elena hears a disturbing story about the Salvatore family from a stranger.

In a flashback sequence, Stefan reveals the Salvatore family history to Elena. Elena demands that Stefan explain the frightening events that have been happening in Mystic Falls. In flashbacks, Stefan explains how his rivalry with Damon began. Back in the present, Damon impulsively takes control of Vicki’s future, and a confused and frightened Vicki runs away. Finally, Sheriff Forbes and Mayor Lockwood take steps to protect the town.

As Vicki’s behavior becomes more dangerous, Stefan tries to help her. Elena tries to convince Jeremy to stay away from Vicki. Caroline gives Bonnie a necklace she took from Damon to wear with her Halloween costume, and when Damon tries to take it back, he is surprised by Bonnie’s abilities. Bonnie discusses the incident with Grams and learns more about her family’s past. Trying to cheer Vicki up, Matt takes her to the high school’s haunted house, but the evening soon takes a terrifying turn.

On his birthday, Stefan is surprised by a visit from Lexi, one of his oldest friends. Still upset by the events at the Halloween haunted house, Elena does her best to stay away from Stefan, but Lexi gives her some unsolicited relationship advice. Elena and Jenna are surprised by a change in Jeremy’s behavior. At Damon’s insistence, Caroline tries to get his medallion back from Bonnie. Finally, Damon’s offer to help Sheriff Forbes has sudden and tragic results.

Jeremy gets a break from the mysterious new history teacher, Alaric Saltzman and introduces Alaric to Jenna. Bonnie is having terrifying dreams about one of her ancestors. Despite Elena’s efforts to smooth things over, Bonnie and Caroline continue to argue over the medallion. When the girls hold a séance to help them decide what to do, the results are stranger than any of them expected. Matt comes to Caroline’s aid when she needs a friend. Damon finally reveals to Stefan the stunning reason he has returned to Mystic Falls.

After reading the journal left by one of the Gilbert ancestors, Jeremy is inspired to return to his hobby of sketching fantasy creatures, a talent he had abandoned when his parents died. Much to the surprise of their friends, Matt and Caroline continue to hang out together. When Sheriff Forbes tells Damon there has been another attack, he offers to track down the killer and learns a startling piece of information about the town’s founding families. Alaric steps in to help during an awkward scene with Jeremy, Tyler and Mayor Lockwood. Stefan and Elena come to a new understanding, but everything changes when Elena accidentally makes a devastating discovery.