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.

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.

The second season begins with Elena discovering her uncle John's bloody body and learning Jeremy's fate, and Damon realizing that Katherine has returned. Meanwhile, Caroline is taken to the hospital following a car accident, and Tyler's mysterious uncle Mason arrives in town.

Elena puts herself in a dangerous position as she searches for the truth about Katherine’s past and what her own future may hold. Knowing that Stefan would never agree to her plan, Elena swears Caroline to secrecy. Damon uses a new-found confidant to help him try to discover the real purpose and power of the moonstone. Jeremy and Bonnie meet Luka, a new student with a surprising family history.

Damon is willing to go to extraordinary lengths to prevent Elena from being a victim of Klaus’ plan to break the curse. Damon’s actions put him at terrible odds with Stefan and the tension that started brewing between the brothers over their differing opinions of how to help save Elena’s life blows up into full-scale conflict. Tyler returns to Mystic Falls after receiving a disturbing phone call. With the full moon marking the arrival of the sacrifice ritual, Stefan and Elena spend a romantic day together — afraid it might be their last.

With help from Elena and Bonnie, Alaric tries to decipher the meaning behind his recent discovery Elena and Rebekah engage in a mean-girl power struggle, until Rebekah finally reveals some of her family's ancient secrets and the violent past she shares with Klaus and Elijah. Damon tries a reckless new approach to make a breakthrough with Stefan, and they're both surprised by an unlikely ally.

Damon and Stefan focus a new project that will bring them closer to destroying Klaus, and they quickly bring Elena, Caroline and Matt in on the plan. After Klaus threatens someone close to Bonnie, she has no choice but to work on the spell he needs. Meanwhile, Klaus and Rebekah find the perfect motivator to convince Finn to cooperate with them, but Rebekah is more interested in her own brutal plan to take revenge on Damon. Stefan’s emotional turmoil leads him to a dangerous confrontation with Klaus and, later, to a heartbreaking moment with Elena.

After making a decision that infuriates Klaus, Elijah proposes a life-changing challenge for Rebekah. Caroline finds that her carefully laid plans for the perfect Senior Prom night are disrupted by Elena, so she turns to an amused Klaus for a solution. Determined to get through to Elena, Damon and Stefan both attend the prom, but the evening begins to spiral out of control despite their efforts. When Elena suddenly lashes out in a way no one could have predicted, Matt turns to Rebekah for help. Finally, Bonnie makes a terrifying discovery, and Klaus receives a message that could change everything.