The Vampire Diaries (2009)

S2E17 Know Thy Enemy

Title: Understand Your Opponent Plot: Elena and Alaric direct their anger towards John after Isobel's sudden appearance leaves Jenna feeling crushed. Meanwhile, Bonnie teams up with Damon and Jeremy to uncover the spell necessary to tap into her ancestors’ strength. Struggling with her feelings, a heartbroken Caroline is uncertain about her relationship with Matt. In a surprising twist, Stefan and Damon discover they possess a new advantage.