The team hunts drug dealers selling fentanyl, which has been linked to multiple overdoses around the city. Tay and Burgess discover a bloodied child who shares a twisted secret about his home life. Mouse contemplates reenlisting in the Army. Platt informs Tay about her next assignment.

The district is in a state of change - Lindsay has moved to New York- and the CPD is under scrutiny about the corrupt nature of its institution. Under the watchful eye of the city, the team attempts to bust a gun deal that quickly turns dicey when innocent civilians and children get involved. Tension erupts when Chief brings in Denny Woods to review the shootout, and Halstead becomes a key player in the outcome of the case.

When Intelligence busts a meth lab run by gang leader Marshall Carter, they uncover a re-homing scam in which children adopted from foreign countries are abandoned, then sold online. Meanwhile, Atwater struggles with the difficult decision about whether to move his siblings Jordan and Vinessa to a safer environment outside of Chicago.

When Atwater disappears at the house of a convicted felon, the evidence doesn't look promising - with his belongings and his blood left behind. Intelligence rallies to rescue him before it's too late. And Atwater struggles for survival faced with not only his captor but also a difficult connection to his past.

Intelligence investigates a string of bombings targeting members of the media. Racing against a ticking clock, the team enlists Firehouse 51 to help examine the devices and prevent the next attack.

The crossover continues on Chicago Fire S06E013 Hiding Not Seeking (II).

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.

Bad heroin is causing overdoses in Chicago, and Intelligence is a man down with Voight suspended. Antonio takes charge, but Ruzek undermines his authority.

Atwater goes undercover to bring down the longtime head of a criminal enterprise and becomes entangled in a situation that tests his allegiances as well as his conscience.

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

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.

The team responds to the shooting of a 5-year-old girl and must work the case while facing new obstacles that come from the heightened attention on police reform. Atwater is targeted by a group of officers who want to hurt him for standing against the blue wall. Voight questions whether he's cut out for a new form of policing as he manages oversight from the CPD's deputy superintendent.

Ruzek and Burgess discover a child walking alone in the middle of the street, and when they take her home, they discover that her entire family has been murdered. Upton is approached with a job offer from the FBI.

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.