Bloodlines

Damon's arrival causes the mysterious man to flee. He takes Elena to Georgia to see Bree, a witch and his old flame, hoping she can help unlock the tomb to free Katherine. Unbeknownst to Damon, Bree contacts Lee, Lexi’s boyfriend, who is seeking revenge for Lexi’s death. Elena saves Damon, and he kills Bree after she tells him to find Emily's spellbook. In Mystic Falls, Stefan talks with Bonnie's grandmother to help Bonnie accept her emerging powers and legacy as a Bennett witch. Jeremy meets a girl named Anna, who seems to possess knowledge of Mystic Falls' hidden history. Upon returning, Stefan reveals to Elena that he saved her the night her parents died and that she is not their biological daughter. Although shaken, Elena forgives Stefan after he reaffirms his love for her. Alaric sits at the Mystic Grill and recognizes Damon as the vampire who murdered his wife.

Plot summary from Wikipedia (CC BY-SA 4.0). Source