Determined to protect his sister, Jeremy makes a decision that will change everything; Bonnie makes a secret deal that has heartbreaking consequences.

In the fourth season premiere, Elena awakens after the accident to find the thing she dreaded most has come true. Damon is furious with Stefan, and takes out his rage on Matt.

As the fifth season opens, Elena, after a passionate summer with Damon, heads to college nearby with Caroline as her roommate. Plus, a terrifying appearance by Silas (PAUL WESLEY).

Damon is trapped by Dr. Wes, and realizes scary things about his past.

Damon realizes Elena is in danger and enlists Stefan's help to find her. The brothers pay a visit to Aaron, and Damon shocks Stefan by revealing his first-hand knowledge of Aaron's family. In an attempt to stop Damon, Dr. Wes unleashes his secret weapon, forcing Damon to deal with a part of his past he thought was gone forever, as well as the consequences of his decades-long plan for revenge. Meanwhile, Elena is horrified by Dr. Wes' confessions about the dark history of Whitmore College and his own ultimate goal. Finally, a frantic Katherine turns to Matt for help, until she realizes that Nadia may be the one who can solve her problem.

Damon and Bonnie are trying to come up with a way to come back from the otherside, while Stefan tries to help Elena start fresh.

As Enzo continues to fight the control over him, Bonnie finds herself at the center of a deadly game and forced to make a heart wrenching decision involving two of the most important people in her life. At the Armory, Alaric researches a mysterious artifact that he hopes will help in their fight to get Damon and Enzo back. Finally, Damon's downward spiral leads him to Tyler Lockwood who attempts to talk some sense into him before it's too late.

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