Intelligence is in pursuit of Derek Keyes, number one on Chicago's Most Wanted list and heroin kingpin. Meanwhile, Halstead tries to get through to Lindsay as her downward spiral continues after her three-week absence from the unit. At District, Olinsky opens up to Platt about a secret from his past. Roman expresses his concerns to Burgess about what she's getting into by marrying Ruzek.
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.