Detective Sergeant Hank Voight and his elite Intelligence Unit at the Chicago Police Department combat atrocious offences and bring criminals to justice.
A string of stash house robberies lead back to an unlikely individual. Voight confronts a key witness in the Bingham investigation.
The team investigates a rash of car jackings and finds the truth is more complicated than they realize. Burgess makes a discovery about a previous case that will change her life forever.
Voight and the team delve into a cold case in search of clues to solve a shocking new crime. With its focus on buried memories, the case sparks concern for Burgess and Ruzek about Makayla’s mental healing.
While trying to find the pimp, Intelligence stumbles on the women's shelter where he's scouting out girls. And Burgess moves the case forward with a series of confidential tips, but risks putting her informant in harm's way.
Ruzek's search for the daughter of an old family friend leads the team into a serious drug investigation. Burgess and Ruzek struggle to move on from the emotional aftermath of Makayla's abduction.
A cop is murdered, and suspicion falls on someone who has been holding a grudge against the officer. Intelligence works hard to solve the case, but Deputy Superintendent Samantha Miller is hesitant to defend him until she knows the whole story.
Ruzek reunites with an old colleague to take down a crime ring, but when things don't add up, Voight and Burgess do some investigating of their own.
When a local business owner is gunned down in his shop, it becomes personal for Atwater, who patrolled the neighborhood as a young cop. Dep. Supt. Samantha Miller comes to Voight with a special request about Andre Cooper.
Halstead’s past resurfaces when a former Army colleague is implicated in a deadly blast. As the FBI launches an investigation into Roy’s disappearance, Upton feels the pressure of the secret she and Voight are sharing.
After a series of brutal home-invasion robberies, Upton immerses herself in the case and finds herself caught between Voight and Halstead.
A picture perfect family is shot dead in their home and the team goes in search of a drug dealer with a likely connection. Voight asks for the help of Vice Sergeant Sean McGrady who has an old beef with Upton. When McGrady turns up dead during the investigation, the case takes an unlikely turn.
One of Voight's friends, Congressman Scott Graynor, is found passed out in his hotel room with a dead Ukranian girl. When Intelligence discovers the murder is connected to a sting and Burgess' boyfriend is working with the Feds, Burgess must choose between compromising her case or her boyfriend's case.
After the murder of a wealthy Chicago man, Atwater and the team dig in to uncover the truth, suspecting there is more to the story than meets the eye.
When a young Latina woman is brutally murdered, Intelligence suspects she may have been working as a drug mule. With Antonio leading the case, the team's investigation takes them into the grim world of meat processing, and the discovery that there may be a different motive behind her death.
Voight employs his new informant to help solve a tricky drug trafficking case. Atwater, who once again struggles to reconcile his personal and professional life, reaches a decision.
While responding to a call of shots fired, Voight, Antonio, Halstead and the team come across a secret battered woman's shelter and discover the owner has been wounded and a resident of the shelter has been kidnapped. Burgess and Roman go undercover to track down a man robbing people by catfishing them on a dating app. Lindsay opens up to Halstead about her past.
Ruzek and Atwater are tasked with making an arrest after a high-profile shooting. The situation becomes complicated when it's clear someone doesn't want them to make it back to the station.
Intelligence tracks down a vigilante killing rapists. The investigation hits home for Burgess, who begins to question if the men who attacked her sister truly paid for their actions.
When a basketball star is found murdered after an anti-police rally, Intelligence navigates a politically charged environment to track down the killer. To complicate matters further, Woods' daughter Brianna is tangled up in the case.
Ruzek's father goes missing, and the team races to find him before it's too late.
A wellness check on a family reveals signs of foul play and Upton is determined to find the parents and young daughter. As Hailey delves further into the troubled family dynamics, she finds herself reflecting on her own childhood trauma.
When a gang from El Salvador infiltrates Chicago, Intelligence works with a visiting detective to put an end to the crew's brutal tactics. Antonio finds himself getting close to the Salvadoran Detective, Marcella Gomez, only to learn she has a hidden motive for being in Chicago. Meanwhile, Voight learns that the body of his son's killer has been found.
The shocking murder of a young pregnant woman leads the team on a desperate hunt for the killer, revealing something even darker than expected. Burgess has to make a tough decision about Makayla.
With a World Trade conference in Chicago, all members of intelligence are undercover in various protest groups to determine potential threats. Ruzek, infiltrates the Black Grid group and befriends Sierra. When she ends up dead intelligence is suspicious of an Argentine Secretary, Fabian Sosa. Voight and Olinsky question Sosa about the death and the team enlists Mouse to help with their tech needs in tracking Sosa. Meanwhile Halstead’s brother, Dr. Will Halstead shows up in town for an undetermined amount of time and is already stirring up trouble.
A string of bombings is targeting members of the media; the team enlists firehouse 51 to help examine the devices and prevent the next attack. (Hiding Not Seeking (2) Chicago Fire S06E13)