"Isobel" is the 21st. episode of the first season of The CW television series, The Vampire Diaries and the 21st episode of the series overall. It originally aired on May 6, 2010. The episode was written by Caroline Dries and Brian Young and directed by J. Miller Tobin.
Plot
Isobel (Mia Kirshner) and Alaric (Matt Davis) talk at the Grill. Alaric asks Isobel why she left him to become a vampire and she says that is what she always wanted. Isobel wants to meet Elena (Nina Dobrev) and asks Alaric to arrange a meeting for her but he refuses to do it and leaves. Isobel follows him and attacks him at the parking lot. She threatens to kill all his students if he will not do what she asked and leaves.
At Mystic High Alaric sets Matt (Zach Roerig) and Tyler (Michael Trevino) to work together and help to build the Founder's Day float before he sees Elena and Stefan (Paul Wesley) from afar and leaves. The two friends still do not talk to each other after Tyler made out with Matt's mother, Kelly, even though Tyler tries to apologize. Meanwhile, Caroline (Candice Accola) asks Bonnie (Kat Graham) what is going on between her and Elena but Bonnie does not want to say.
Alaric gets Elena and Stefan at his classroom to talk to them about Isobel's request. Damon (Ian Somerhalder) joins them a little bit later since Alaric called him. Damon is surprised hearing that Isobel is in town and wonders if she is working with John (David Anders) and why she wants the Gilbert device. When they tell him that the only thing she wants is to meet Elena, Damon tells Elena that she does not have to meet her if she does not want it but Elena agrees and meets her later at the Grill.
Elena and Isobel meet at the Grill while Stefan sits a few tables away for protection. Isobel is surprised of how much Elena looks like Katherine and says that Katherine found her after she became a vampire. Elena wants to know who her father is but Isobel has no any intentions of telling her. Instead, she reveals the real reason she wanted to meet Elena which is no other than the Gilbert device, the same one that John wants. Elena asks how she knows John and Isobel admits that John was in love with her in the past and that he was the one who told her about vampires. Elena refuses to help her with the device and Isobel threatens her that she has to do it. She leaves and Bonnie enters the Grill. She sees Elena upset but she turns around when she sees Stefan approaching her.
At the Gilbert house, Jeremy (Steven McQueen) keeps calling and leaving messages to Anna (Malese Jow) from who he did not hear since she went home and found her mother dead, something that Jeremy does not know. John hears Jeremy leaving the message and talking to Jenna (Sara Canning) about it and he tells him that if he wants to talk about girls he is there. Jeremy is surprised by the offer and he just leaves.
Isobel comes back home and finds Damon waiting for her. The two of them have a talk and Isobel tells Damon that it is Katherine the one who wants the device and Damon warns her to stay away from the people he cares about. Before he leaves, he delivers a message for Katherine; that if she wants the device then she should come and take it herself.
Bonnie shows up at Elena's house feeling bad for not talking to her at the Grill while she saw how upset she was and she apologizes. Elena tells her that she met her birth mother. Elena tells her about the device and later, Bonnie asks her to come and she shows Elena Emily's spellbook. Bonnie explains that Emily was the one responsible for all of Jonathan Gilbert's inventions since she was casting spell on them making him believe that they were working. From the book they learn that the device is a weapon against the vampires and that it's consisted of two parts. Damon only has one part of it.
Back outside at school's yard, Isobel shows up in front of Elena saying that she wants to be involved in her life. Elena refuses her "offer" and Isobel points out that she knows every one of Elena's friends; Bonnie, Caroline, Matt and her little brother Jeremy. To show her that she can hurt them without second thought, she has one of her compelled friends to jump on the float Matt's working on pinning his arm underneath. Tyler and Stefan run to help Matt, while Isobel's other compelled friend kidnaps Jeremy. She promises Elena to kill him if she will not bring her the device.