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.
District 21 of the Chicago Police Department is made up of two distinctly different groups: The uniformed cops who patrol the beat and deal with street crimes, and the intelligence unit, the team that combats the city's major offenses, such as organized crime, drug trafficking and high-profile murders. Leading the intelligence team is Sgt. Hank Voight, a man not against skirting the law in the pursuit of justice.
Demanding and tough, only those who can take the heat survive under Voight's command. Take Det. Antonio Dawson, for example. Despite a troubled history with his boss, Dawson has ambitions of running the unit. If that means facing off against Voight every day, he'll persevere. From the street cops with dreams of moving up to the elite crew who are already in, life on the job is a daily challenge.