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' own neighborhood is violently abducted.
A homicide in the neighborhood where Burgess and Ruzek reside forces the team to investigate complicated relationships within the tight-knit community they call home.
A string of violent robberies across the city digs up one family's secrets; a surprising detail of Voight's past resurfaces.
Atwater reunites with an old friend from his academy days after a bombing rocks downtown Chicago.
Torres is dragged into a deadly conspiracy when a routine errand takes a violent turn.
When Kelton is found murdered, Voight's grudge against the mayor-elect puts him under suspicion; Upton and Halstead are eager to prove their sergeant's innocence, but the more evidence they gather, the closer they come to doing the opposite.
When Atwater goes undercover in a drug syndicate, he learns there may be more to its kingpin than meets the eye; Halstead tries to join Atwater undercover, but finds himself at a disadvantage; Voight petitions the brass to show Ruzek leniency.
After a botched carjacking turns out to be something much bigger, Voight's unit goes toe-to-toe with a smart drug kingpin who only works with women; new recruit Vanessa Rojas struggles with the transition from under cover to intelligence.
After zeroing in on a suspect responsible for bioterrorism, the P.D. prepares to undertake its biggest manhunt yet; Upton is torn between helping track down the perp and providing emotional support to a scared young girl who needs her.
A murder in a Bulgarian neighborhood results in a challenging investigation when locals won't talk to police; Ruzek has a clash with a patrol officer.
With the threat of a gang war looming, Voight and Ray Price must organize a peace summit to end the bloodshed before more innocent people get hurt; Burgess evaluates her future with Blair.
Intelligence's investigation into the murder of Burgess' boyfriend threatens to reveal a dark side she was unaware of; the real motivation for his murder uncovers a much more unsettling truth.
A violent crew is hitting pharmaceutical delivery trucks and stealing drugs, but their motivation is more complicated than just money; the case tests Upton and Ruzek's relationship.
Antonio struggles with his guilty conscience as he tries to take down a major drug dealer; Voight takes a shot at Kelton to protect his team.
With Kelton's election all but assured, Voight and his team must go off-book in a last-ditch effort to save Intelligence from getting axed.
The victim of a murder-arson case is discovered to have been wearing a CPD issued wire at the time of his death; Burgess meets her new partner; Cmdr. Crowley questions Lindsay about the night intelligence pursued Justin's killer.
Voight and the team search for answers after discovering a man badly beaten and learning that his fiancee is missing; Lindsay asks Halsted a surprising question; Platt is berated by Fogel for going over his head.
After Platt is physically assaulted while getting into her car, she's rushed to Chicago Med, where Mouch finds himself being questioned; Antonio and the team look for previous threats against Platt.
Lindsay and Ruzek respond when a car crashes through a crowd of concert goers and a gunman opens fire; Burgess sees Atwater's brother somewhere he shouldn't be.
The body of a college student is found with a backpack full of a drug linked to deadly overdoses around the city; Tay finds a bloodied child with a dark story about his parents; Mouse looks to re-enlist in the army.
While responding to a complaint, Burgess and Sorensen find the body of a 16-year-old girl in a baseball player's (Billy Burke) house; Lindsay receives a mysterious delivery that might have ties to her past.
After escaping from a New York prison, convicted killer Gregory Yates (Dallas Roberts) heads to Chicago; SVU members Benson and Tutuola help investigate a triple homicide in Chicago; the team seeks a connection between Yates and a missing woman.
Burgess finds heroin in a duffel bag belonging to a mild-mannered and respected college professor; Roman talks to Platt about his career; Halstead takes an off-duty security job working for the attractive owner of a medical marijuana clinic.
Lindsay, Halstead and Mouse search for a connection when two shootings take place in gang territory; a candlelight vigil is held for a young boy who was murdered in the first shooting.
During a bank run for his off-duty security job, Halstead and his co-workers are attacked by a violent robbery crew, which leads to a shootout; Voight and Lindsay talk to a dispensary owner who says her business has received threats from local gangs.
The team discovers a secret battered woman's shelter and learns that the owner has been wounded and a resident has been abducted; Burgess and Roman track down a man who has been catfishing people on a dating app to rob them.
When Burgess and Lindsay respond to a call about a stabbing, the assailant turns out to be a kidnapping victim escaping her captor; Ruzek accuses Roman of having feelings for Burgess.
After a cold and unmoving newborn baby is discovered in a duffel bag on a Chicago lakefront, Chicago Med is able to provide information that helps zero in on a suspect; Roman and Burgess grow closer.
Lindsay and Halstead discover the youngest daughter is the only survivor of a shooting at a family home; Antonio and Olinsky investigate a pyramid scheme self-help group; Platt tries to convince Crowley that Burgess and Roman should remain partners.
When the body of a single mother is found in the trunk of her car, the team is shocked to learn the victim had contact with Voight's reformed son.