Damon takes a trip to Georgia, where he surprises an old flame, Bree and enlists her help to figure out how to open the tomb. In the process, Damon comes face to face with someone who is determined to make him pay for past wrongs. Stefan opens up to Grams in his effort to help Bonnie overcome her fears and accept her powers. While researching his history paper in the public library, Jeremy meets a cute-but-geeky girl named Anna who has her own theories on the folklore of Mystic Falls. When Damon returns from Georgia, Stefan is waiting with news that will change their world.

Damon, Elena and Stefan attend the school dance with a 1950s' theme, where Alaric introduces himself to Damon. Stefan and Damon try to figure out the identity of the new vampire in town, Stefan gives Elena jewelry filled with Vervain to protect her family and friends. To make ends meet Matt takes a job at the Mystic Grill. Ben comes to help Bonnie when he notices Damon is bothering her.

In flashbacks, Stefan and Damon recall the long-ago actions taken by townspeople including their father, Guiseppe Salvatore, and Pearl, leading to the devastating events that caused the rift in their relationship. In the present, Bonnie's date with Ben takes a frightening turn. Elena helps Stefan as he and Damon race to find the missing journal that belonged to Elena's ancestor. Stefan learns the reason behind Alaric's interest in both the journal and the town's history. Damon discovers that an old acquaintance has returned to town with an agenda he understands.

Stefan helps Elena and Bonnie out of a dangerous situation. Jeremy asks Anna to a party in the woods, unaware that she has her own reasons for wanting to meet him there. When Stefan, Damon, and Elena work with Bonnie and Grams to open the tomb, everyone is shocked by what they discover.

Matt and Caroline are surprised by the sudden reappearance of Matt’s mother Kelly. Stefan and Elena are worried about Damon’s new attitude. Damon is asked by Sheriff Forbes to take part in a fund-raising bachelor auction. Alaric discovers shocking secrets from his own past. With help from Jenna and Stefan, Elena is determined to find out everything she can about her birth mother, but the truth may be more than she can handle.

Anna brings a surprising guest along when she pays a visit to Damon. Elena and Stefan go on an awkward double date with Caroline and Matt, but Stefan and Matt find they have some common ground. Jenna reunites with her old friend Kelly, and Jeremy’s relationship with Anna takes an unexpected direction.

When Stefan and Damon make a dangerous new enemy, Stefan suddenly finds himself in a perilous situation. Damon and Elena try to convince Alaric to work with them to help Stefan. Matt is hopeful that his mom, Kelly, may be back to stay. After her car breaks down in a storm, Caroline make a horrific discovery that shocks everyone in town.

At the Founder’s Day Gala, Elena and Caroline compete for the title of “Miss Mystic Falls” against other girls from town, including Tina Fell and Amber Bradley. Elena is happy to have Bonnie back in town, but Bonnie still has issues to work through. John Gilbert attempts to intimidate Damon, but his plan doesn’t have the desired effect. Damon discovers that Stefan is hiding a dangerous secret that could impact everyone in town.

While Stefan struggles to come to terms with his past, both he and Damon reveal parts of their history to Elena, until she finally learns the truth about how they became vampires. Pearl has an ugly confrontation with Johnathan Gilbert. Damon and Alaric try to find a mysterious invention before Johnathan does. The friendship and flirtation between Jeremy and Anna continues to grow.

Isobel returns to town and stuns Alaric with her attitude and her demands that he arrange a meeting with Elena. When mother and daughter finally meet, Isobel refuses to answer most of Elena’s questions, but reveals that she will stop at nothing to find the mysterious invention Johnathan Gilbert has been searching for. Isobel’s dangerous actions lead Stefan, Damon and Bonnie to step in and help Elena deal with the situation.

Founder's Day has finally arrived, and everyone is busy with last-minute preparations for floats and fireworks. Stefan is uncomfortable with Damon's new attitude toward Elena, but Elena is more concerned about repairing her relationship with Jeremy. Jeremy is worried about Anna, but not sure he's on board with her latest plan for the future. While Caroline is enjoying her day as Queen of the celebration, she also tries to help Matt and Tyler get their friendship back on track. Finally, although Damon and Alaric do their best to stop him, Johnathan Gilbert sets a plan in motion that brings Founder's Day to an end amid chaos, destruction and death.

Mystic Falls screens "Gone with The Wind" in the town square, and Damon's memories of Katherine in 1864 mix with the reality of present-day Elena. Stefan pays a steep price after trying to prevent a tragedy, and Sheriff Forbes makes a dangerous mistake while trying to keep everyone safe. Multiple lives hang in the balance as the consequences of the sacrifice ritual play out to a horrifying conclusion.

On the morning of Elena’s 18th birthday, Caroline is busy planning a party, but Elena is focused on searching for any clues that might help her discover where Stefan is. Damon is also searching for Stefan, while trying to protect Elena and keep her from doing anything that would draw Klaus’ attention. Meanwhile, Klaus and Stefan are busy trailing a werewolf named Ray Sutton. Now working at the Mystic Grill along with Matt, Jeremy is struggling to understand why he keeps seeing the ghosts of Vicki and Anna since he was brought back to life by Bonnie’s magic. Meanwhile, Alaric does his best to watch over Elena and Jeremy, while dealing with his grief over Jenna’s death. Finally, Caroline and Tyler face a new and unexpected challenge.

Klaus puts a plan in motion that will give him even more power, but even with the unwilling participation of werewolf Ray Sutton, things don’t go exactly as Klaus had planned. Damon and Alaric reluctantly go along with Elena’s new strategy to find Stefan, leading Damon into a dangerous fight with an unexpected enemy. Jeremy turns to Matt for help as he continues to try to understand what the ghosts from his past want from him. Unaware that Caroline is in need of his help, Tyler faces an emotional confrontation with his mother.

Still in Chicago, Klaus uses Gloria, a witch he knew long ago, to help him track down missing information that will explain why his plan isn’t working. Gloria’s spells reveal intriguing glimpses of the truth, but she soon realizes she needs Stefan’s knowledge to complete the puzzle. When Stefan suddenly finds himself in danger, help comes from a surprising ally. Back in Mystic Falls, a frustrating new enemy pushes Damon over the brink and he lashes out in a way that will have lasting consequences. Caroline struggles with her own emotional issues, even as she tries to help Elena face her feelings. Jeremy makes a brief but disturbing breakthrough with one of his ghostly visitors, leaving him more confused than ever. Finally, Bonnie has a strange encounter that will affect everyone.

Despite all that has happened, Caroline is determined to see that Elena, Bonnie, Matt and Tyler all enjoy a traditional Senior Prank Night before the school year begins at Mystic Falls High School. However, when uninvited guests show up, it doesn't take long for the evening to take a deadly turn. Damon convinces Jeremy that he can use his new connection to the other side to help find a way to defeat Klaus. Finally, Klaus deepens his hold on Stefan and uses him for increasingly violent and dangerous purposes.

On the first day of their senior year, Elena, Caroline, Bonnie and Matt are still reeling from recent events, while Tyler seems to be enjoying everything a little too much. Damon is annoyed by a new houseguest, and everyone is surprised by the arrival of a new student in Alaric's history class. Matt asks Bonnie for help when he realizes he made a serious mistake. Meanwhile, Stefan continues to carry out his latest assignment from Klaus.

As Mystic Falls prepares to celebrate the traditional Illumination Night, the town is invaded by spirits of the dead. After a particularly violent encounter with an angry spirit, Damon asks Bonnie to find the reason behind the ghosts' surprising power. Elena convinces Jeremy to use his connection to the other side to help her find a new way to reach Stefan, leading Jeremy to a terrible choice. Finally, Alaric discovers a long-hidden clue to the past.