In Pilot, she was first seen as entering Mr. Tanner's History Class, introducing her self to him and the class, while looking at Stefan. Stefan was shock and a little fearful of her when she passed him and sat down behind him. After class, Stefan confronted Elsa on what she was doing here and her humanity, and Elsa retorted that she can easily turn it off and start killing people, beginning with Elena Gilbert.
She was at the Mystic Grill later on, where she met Caroline Forbes, Bonnie Bennett and Elena, who was sitting with Stefan. Caroline invited her to sit with them. They had a conversation, and Elsa let it slipped that they are both siblings. Caroline invited them to Back to School Party. While Stefan ask Elena, Elsa had other plans at the party. Drinking booze and intoxicated human blood.
At the Salvatore Boarding House, Stefan confronted Elsa again, telling her not to drink at the party, when she lied that she wont. Their distant nephew, Zach Salvatore, has entered the room, holding out a newspaper about the recent killings around Mystic Falls. Elsa, knowing who did it, didnt say anything. Zach accused of them of the killings and why they belong.
At the falls, Elsa watched Stefan interact with Elena Gilbert, as she wondered into the forest when she surrounded by fog, and calling out his name. The fog disappeared. Her older brother, Damon Salvatore, returned. Elsa is happy with Damon being here, and they went out to join on a hunt for human blood.
They hunted down Vicki Donovan, nearly drained her in blood. Damon left, and Elsa quickly cleaned herself up and hearing Elena and Jeremy Gilbert coming out, she lied, calling out for help. Making her a completely innocent human on finding the bleeding, unconscious Vicki. Jeremy and Elena were shocked, Jeremy was freaking out, as she lied about what had happened.
Jeremy picked up Vicki and carried her back to the party. Elena thank her before walking off. Elsa was staring after her with knowing, smug smile on her face, before walking home.