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.

Olinsky's daughter remains in critical condition following a massive fire - leaving Intelligence on edge, but more determined than ever to track down the suspect. Voight opens up the case, knowing that he has Stone and his team's full support in the investigation, and all of Firehouse 51 behind him to examine potential origins of the fire. The crossover starts on Chicago Fire S05E15 Deathtrap (I). It continues on Chicago Justice S01E01 Fake (III).

After receiving a distressing 911 call, Burgess enlists the team's help to track down a girl caught up in a sex-trafficking ring.

In the Season 3 finale, the team investigates the murder of a single mom who was in contact with Voight's now-reformed son, who was himself brutally assaulted. Meanwhile, Roman makes a major decision and Crowley plans to make changes within the unit.

When a young officer is shot dead in the lobby of an apartment building, Intelligence looks to the latest known offenders who have threatened the police. But when a second officer is killed, the team finds that they are dealing with someone who is highly trained and knowledgeable.

In an attempt to dig himself out of a hole and save someone close to him, Antonio crosses a line that puts the entire team at risk.

Voight and the Intelligence Unit focus all their effort and resources into investigating the disappearance of an exotic dancer who served as a long-time criminal informant for their team

When Upton and Ruzek answer an emergency call to an abandoned house, their investigation leads them down a dark path.

As Richard Beck's timeline for a deadly attack moves up and Samantha panics, Ruzek and the team scramble to get ahead of unprecedented disaster.

The body of a 15-year-old girl is found crushed in an abandoned building after she runs away from a treatment center for troubled girls. Voight sends Halstead undercover as a guard to work from the inside at the center, where he believes the girls are trading sexual favors for something in return.

After encouraging her sister to spend a night out with friends, Burgess wakes to find that Nicole never made it home. As the guilt begins to eat at Burgess, the team in Intelligence bands together to make finding Nicole their main priority.

Halstead's partying with Camila unintentionally puts him in the middle of a drug-related homicide. He's forced to choose between loyalty to his unit and his girl. Meanwhile, Voight finally discovers the mole in his unit.

Tensions run high as Intelligence seeks justice for Olinsky after he's stabbed in prison; Antonio's loyalty is put to the test; Woods looks to take down Voight once and for all. Season Finale.

Atwater goes undercover to take down a gun-trafficking ring, but discovers an officer from his past is undercover in the same organization.

As the team investigates the stabbing of a father with two young daughters, they begin to suspect there is more to the story than meets the eye. The FBI investigation into Roy Walton’s death intensifies while Voight, Upton and Halstead feel the heat.

After an explosion rocks the case, the team scrambles to finally take down Escano as everyone nears their breaking point.

Still reeling from the death of informant Anna, Voight faces a new threat as he tries to keep the neighborhood clean. New wrinkles develop in the Upton, Halstead and Voight dynamic. The team gets a new chief.

Retired Commander Perry enlists Voight and the team to help extract his cop nephew from a unit of corrupt officers who are robbing drug dealers. When things go bad Voight must take down a younger, more violent version of himself. Meanwhile, Lindsay struggles to stay clean. At the same time a woman from Olinsky's past reaches out to him.

A bust to bring down a heroin kingpin goes horribly awry. Olinsky reveals a dark secret from his past, and Halstead tries to get through to a spiraling Lindsay.

The team investigates a murder in which the victim appears to have been wearing a CPD-issued wire. Burgess works a case with a new partner. Crowley questions Lindsay about the night that Intelligence pursued Justin's killer.

When the team is called to an in-progress bank robbery, they come across Detective Hailey Upton trying to take over the crime scene with her Robbery-Homicide unit - butting heads with Voight in the process. As the robberies continue to be executed around the city, Lindsay is forced to make a decision in the heat of the moment.

Intelligence crosses with a mayoral candidate while investigating the fatal shooting of a well-known defense attorney. Antonio returns to work but questions his own judgment when an operation goes sideways.

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.

With the FBI closing in on the Roy Walton investigation, Voight and Halstead strategize on a way out. After a city bus driver is shot by a passenger, the team investigates a possible abduction.

While out for a jog, Upton witnesses a horrible car crash and risks her own life to save the passengers. After learning more about the victims, the team must track down the man responsible for the brutal crash.