Caroline wakes up in the hospital and is horrified to learn that she is turning into a vampire. Meanwhile, Damon suspects that Mason may be a werewolf, and Bonnie gets angry with Damon and sets him on fire. (TV Guide)

Elena, Damon and Alaric travel to Duke University to research Isobel's past and her studies in paranormal phenomena. Meanwhile, Stefan faces a terrifying new danger in the woods, and Tyler learns a surprising secret about his uncle Mason. (TV Guide)

Katherine reveals to Stefan secrets about what really happened in 1864 when she turned him into a vampire. Meanwhile, Damon tries to resolve his conflict with Mason, and Tyler attempts to get Mason to tell him the truth about the Lockwoods' dark past. (TV Guide)

Mason reveals to Tyler the details of the family curse and informs the sheriff that Stefan and Damon are vampires. The sheriff then makes plans to capture the brothers and kill them. (TV Guide)

Damon kidnaps Mason to learn why he is helping Katherine and why he wants the mysterious moonstone. Meanwhile, Stefan tries to retrieve the moonstone after learning it is hidden in a well, but the attempt quickly becomes life-threatening. (TV Guide)

The Lockwoods throw a masquerade ball, and Stefan and Damon try to prevent Katherine from wrecking the party. Meanwhile, Matt and Tyler get into trouble when they start drinking shots with some friends. (TV Guide)

Elena is abducted by a masked stranger at the masquerade ball, and Stefan and Damon learn surprising information about vampires in the distant past. Meanwhile, Jeremy helps Bonnie after she casts an exhausting spell, and Caroline tries to make life easier for Tyler now that he is a werewolf. (TV Guide)

Katherine reveals to Elena her bloody past back in 1490 Bulgaria when she was pursued by the world's oldest known vampire. Meanwhile, Bonnie befriends a warlock who recently moved to Mystic Falls with his father. (TV Guide)

Jeremy tries to retrieve the moonstone from Katherine, but his plan goes horribly wrong. Meanwhile, Tyler discovers a video of his uncle's first transformation into a werewolf, and Elena attempts to sacrifice her life to save her loved ones. (TV Guide)

Caroline helps Tyler prepare for his first transformation into a werewolf. Meanwhile, a stranger shows up in Mystic Falls searching for Mason; Elijah confronts Elena in her house and offers to make her a deal; and Bonnie and Luca work together on a magic spell with the moonstone. (TV Guide)

Damon tries to save Rose after she is bitten by a werewolf, but her increasingly violent behavior puts everyone, especially Elena, in danger. Meanwhile, Tyler reveals his true feelings for Caroline, and Jonathan Gilbert makes a surprise return to town. (TV Guide)

Elena is shocked and dismayed when John Gilbert, her biological father, returns to Mystic Falls. Meanwhile, Caroline is taken hostage and Tyler deals with the news that she and other vampires may have murdered his uncle. (TV Guide)

Stefan and Elena go to a lake house for a romantic weekend, but they don't realize they're being followed. Meanwhile, Jenna worries that Alaric isn't being honest with her; and Bonnie deceives Luka to get vital information from him. (TV Guide)

Stefan confesses to Elena that he used to be a monstrous murderer who killed members of her family. Meanwhile, Damon arranges a dinner party for Elijah and plots to kill him during dessert. (TV Guide)

Katherine plays mind games with everyone, but Damon, Stefan and Elena realize they need her to survive. Meanwhile, Alaric makes a surprising confession to Jenna, and Jonas becomes involved in a violent confrontation. (TV Guide)

Isobel arrives unexpectedly and kidnaps Alaric and Elena. Meanwhile, Bonnie tries to increase her powers by harnessing the energy of former witches who were sacrificed, and Katherine steals the moonstone that is the key to the vampire-werewolf curse. (TV Guide)

Elena and Stefan attend a 1960s Decade Dance at school, but Klaus arrives after having taken possession of Alaric's body. His plan is to capture Elena and sacrifice her to end the vampire curse, but Bonnie tries to stop him with her newfound powers. (TV Guide)

Elena brings Elijah back to life by removing the magical dagger from his heart and he reveals to her Klaus' true purpose for breaking the so-called moonstone curse. Meanwhile, a flashback to 1491 reveals how Katherine met Elijah and Klaus. (TV Guide)

Stefan and Elena spend a romantic day together and fear it may be their last one because of Klaus' plan to use Elena as a sacrifice to break the moonstone curse. Meanwhile, Tyler returns to Mystic Falls after receiving a disturbing phone call. (TV Guide)

Elena prepares for the sacrifice ritual planned by Klaus. Meanwhile, Tyler makes his second transformation into a werewolf when the full moon appears, and Damon reveals to Stefan a disturbing new development they must face. (TV Guide)

The second season concludes with lives hanging in the balance as the consequences of the sacrifice ritual become clear. Meanwhile, Damon recalls memories of Katherine in 1864 during a town-square viewing of "Gone With the Wind." (TV Guide)