District 21 of the Chicago PD is made up of two different groups: The uniformed cops who patrol the street crimes, and the intelligence unit who combat the city's offences.
Voight teams up with an unlikely ally to take a killer off the streets while fighting to bring his Intelligence unit back together.
The Intelligence Unit races against time when a man from Torres's own neighbourhood is violently abducted.
A homicide in the neighbourhood where Burgess and Ruzek reside forces the team to investigate complicated relationships within the tight-knit community they call home.
