Miss Mystic Falls

The episode begins with Stefan going back to school. Elena approaches him, surprised to see him there, but he claims that his cravings for human blood are over. At the Founder's Day Gala, Elena and Caroline compete in the "Miss Mystic Falls" contest. Bonnie returns to town and Elena is very happy to have her back, but Bonnie is cold and distant. Bonnie reveals that she feels angry and alienated with Elena because of her association with the Salvatore brothers. At the Miss Mystic Falls contest, Damon tells Elena that Stefan has been drinking human blood again. Stefan is angry when Elena confronts him with this information, and breaks a mirror. One of the Miss Mystic Falls contestants, Amber Daly, sees him do this, so Stefan takes her. Anna shows up at the dance, and Jeremy attempts to apologize for using her to become a vampire. Jeremy tells Anna that he knows that the only reason Anna wanted to be friends with him was so she could use his blood to revive her mother. Anna asks Jeremy how much he knows and he says he knows everything. Anna and Jeremy make up and Anna says she would never do anything to hurt him. Back at the dance, Damon poses as Elena's escort, since Stefan is not there. Later Elena and Damon, with help from Bonnie, locate and subdue Stefan after seeing him in the woods feeding off of Amber. Meanwhile, John Gilbert tries unsuccessfully to intimidate Damon. The episode ends with Elena injecting vervain into Stefan. She and Damon lock him in the cellar in an attempt to help him control his blood urges.

Plot summary from Wikipedia (CC BY-SA 4.0). Source