While working at a sobriety checkpoint, Burgess finds a duffel bag full of heroin in the truck of a respected college professor who claims to know nothing about how the drugs ended up there. Voight decides to hold off on charging the unlikely suspect, and Olinksy and Antonio follow up on a lead to see who is behind the drug smuggling. At District, Roman expresses his desires to become a Field Training Office to Platt, and Mouse sets Halstead up with an off-duty security job working for the attractive owner of a medical marijuana clinic.
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.