Episode 18: Under Control «Confirmed»

In " Under Control " (Season 1, Episode 18) of The Vampire Diaries , Stefan struggles with severe bloodlust while John Gilbert returns to stir up trouble in Mystic Falls, prompting Jeremy to discover the truth about vampires. The episode, which first aired in April 2010, also highlights the danger posed by the supernatural-protection rings worn by John and Alaric, ultimately showing Stefan failing to manage his hunger. You can watch this episode on Apple TV or read a synopsis on Wikipedia .

Watch a clip from this episode where Elena and Stefan discuss Jeremy's growing suspicions: Episode 18: Under Control