When a call comes in about a woman stabbing a man then fleeing the scene, Burgess and Lindsay go investigate and find a young woman with the weapon in her hand. The suspect turns out to be a victim and she tells Olinsky that she was held hostage for months and her kidnapper attempted to psychologically manipulate her into forgetting her identity while he physically abused her. The team sets out to find the woman's abductor before he can harm anyone else. Meanwhile, tensions are high at the station when Ruzek accuses Roman of having feelings for Burgess.