Elena puts herself in a dangerous position searching for the truth about Katherine's past.
Stefan and Damon come to Elena's assistance and, in the process, learn surprising new information.
Stefan and Damon decide on a new plan to deal with Katherine at the masquerade ball. Things take an ugly turn when Matt and Tyler start doing shots.
Katherine chooses a new victim. Bonnie discovers new information about Mason and shares it with Stefan.
Tyler learns more about the Lockwood family curse from Mason, and Sheriff Lockwood receives startling information.
Stefan is shocked when Katherine reveals new secrets about what really happened in 1864. Damon tries a new tactic to resolve his issues with Mason.
Elena, Damon and Alaric go to Duke University to search through Isobel's research, hoping to uncover any clues surrounding the Lockwood family.
When a confused and desperate Caroline leaves the hospital and joins her friends at the Mystic Falls Carnival, Damon wants to take immediate action.
Elena arrives home to a nightmare. Damon is the first to realize that Katherine has returned.
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Damon and Alaric try to stop John Gilbert from setting a plan in motion to bring Founder's Day to an end amid chaos, destruction and death.
Isobel returns to town and stuns Alaric with her attitude and her demands that he arrange a meeting with Elena.
Elena learns what happened when Damon and Stefan were turned. Pearl has an ugly confrontation with John Gilbert. Jeremy and Anna get closer.
Elena and Caroline compete in a beauty pageant. Spencer Locke appears as one of the contestants. John Gilbert tries to scare Damon.
Stefan displays a rare party attitude. Damon's attempt to find out why Elena's uncle, John Gilbert, has returned to town takes an ugly turn.
Stefan is forced into a frightening decision. Matt is hopeful his mom will stay. After Caroline's car breaks down, she makes a shocking discovery.