The Vampire Diaries

Season 2, Episode 17

Episode Title: Know Thy Enemy

Air Date: 2011-04-07

Overview:

Elena and Alaric both lash out at John when Isobel’s unexpected arrival leaves Jenna devastated. Bonnie works with Damon and Jeremy to find the spell they’ll need to harness her ancestors’ power. A heartbroken Caroline doesn’t know what to do about Matt. Stefan and Damon realize they have a new secret weapon.