The Devil Inside (The Vampire Diaries)

"The Devil Inside" is the 15th episode of the third season of the American supernatural drama television series, The Vampire Diaries. It originally aired on February 9, 2012, on The CW.

The episode primarily focuses on Elena Gilbert (played by Nina Dobrev) and her growing concerns and suspicions surrounding Damon Salvatore (played by Ian Somerhalder) and his increasingly reckless behavior. It also delves into the consequences of Esther Mikaelson's, the Original family's mother, plan to eliminate her own children. The phrase "The Devil Inside" refers, in part, to the influence Esther exerts over Rebekah (played by Claire Holt), Finn (played by Casper Zafer), and potentially other members of the Original family, compelling them to act against their own nature and in service of Esther's vengeful agenda.

A key plot point revolves around Bonnie Bennett (played by Kat Graham) struggling with the resurfacing of dark magic influences due to her connection to Esther and the plan to link the Original vampires together, meaning that if one dies, they all die. The episode explores the ethical dilemmas Bonnie faces as she is forced to confront the potentially devastating consequences of her actions.

Furthermore, "The Devil Inside" explores the evolving relationship between Elena and Stefan Salvatore (played by Paul Wesley) in the context of the escalating threats posed by the Originals and Damon’s unpredictable behavior.