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.
A month after Voight’s close brush with death, Intelligence is overwhelmed with cases as they catch a high-stakes drug bust.
After tragedy strikes Intelligence, the unit must persevere during an adrenalized manhunt across the city.
Atwater struggles to find balance as he teams up with a forensic psychologist on an armed robbery case.
ASA Chapman assists Intelligence with a sensitive investigation that drudges up painful memories for Voight.
In the midst of a momentous rainstorm, Intelligence lends support to Officer Cook when she and her partner disagree about an investigation.
Burgess is put to the test as she looks to make an advancement in her career.
Torres is haunted by his previous transgressions as Cook takes on a tense undercover assignment.
The Unit learns the truth about a secret Torres has been keeping as Deputy Chief Charlie Reid puts a focus on Intelligence.
Cook turns to her family when Intelligence faces administrative roadblocks that threaten a kidnapping investigation.
An unexpected visitor causes disruption for Ruzek and Burgess amidst an emotional investigation involving an unidentified young girl.
With the suspects still at large and conditions worsening underground, first responders race against the clock to reach the trapped victims, while the investigation into the assailants comes into focus.
Intelligence makes a gruesome discovery that leads Torres to go undercover at the juvenile detention center where he served time as a teen.
A mounting strret war threatens a community-center project that Atwater is trying to get off the ground.
Ruzek grapples with his father's worsening condition while Intelligence searches for an elusive serial killer.
Voight questions Deputy Chief Reid's motives in enacting a Violence Reduction Initiative across a neighbourhood where numerous gangs are fighting for territory.
