Ep 12. The Devil Inside

Elena is determined to get Caroline's mind off her breakup with Tyler by throwing a girls' day at the lake house. Tyler tries to remedy Klaus's suspicion of him by offering a confession that catches him off guard. Damon and Stefan try a brutal new approach to provoke Elena into turning her humanity back on, and Caroline is frustrated when her attempt to intervene backfires. When Elena finds out Stefan is in trouble, she decides to take matters into her own hands and finds herself face-to-face with a new threat. Meanwhile, Bonnie learns a terrifying secret that threatens the lives of all her friends.