While investigating a drug-related homicide, Intelligence is stonewalled by the 'no-snitch' culture of the neighborhood. And Atwater discovers a personal connection to the case. Meanwhile, the police's own code of silence is put to the test when Upton is asked about Ruzek's rough altercation with a suspect.

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.

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.

Upton brings back an old undercover identity to help take down a meth ring spearheaded by a former criminal contact. And with pressure from Woods mounting, Voight calls in a favor for Olinksy.

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.

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

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.

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.

The team pursues a crafty serial rapist. Sergeant Voight finds himself resisting some old, familiar tendencies in his quest for justice.

After a series of brutal home invasion robberies, Upton immerses herself in the case and finds herself caught between Voight and Halstead.

Officer Kim Burgess fights for her life as the team scrambles to find her kidnapper. Dep. Supt. Sam Miller is desperate to find her son's killer. Voight and Upton deal with the aftermath of their deadly decision. Ruzek struggles with the pressure of the situation.

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.

The team works together to identify the head of the brutal Los Temidos gang. Voight dives deeper into his informant Anna Avalos' past when her undercover role is threatened.

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.

As the team closes in on drug kingpin Javier Escano, Voight is forced to lie to his undercover informant Anna to keep her on track. Their deteriorating trust threatens an increasingly tenuous operation.

When a convicted murderer hijacks a prison van, the team scrambles to find him and the abducted prison guard before it's too late. Burgess questions Ruzek's motives in a case, creating tension between the two.

To distract Intelligence from the investigation into his son, Chief O'Neal forces the team to handle a "dead fish" case. However, when that dead fish turns into a complicated heater case, Burgess is thrown back into difficult memories from her past.

Voight and the team help ASA Nina Chapman pursue a drug runner who dodged prison years ago after Chapman's informant mysteriously disappeared. The investigation takes a turn when Voight uncovers a damaging secret from Chapman's past.

A tragic crime leads the team closer to the Beck family and their deadly ideology. Ruzek makes progress infiltrating the Becks, earning Samantha and Richard's trust with a bold move.

Torres finds himself in the midst of a murder case that hits close to home and threatens to expose his troubled past. As he struggles to reconcile his old life with his new one, Voight keeps a watchful eye.

Ruzek gets mixed up in a case after a late-night poker game is raided. Afraid of becoming like his father, Ruzek struggles to stand down and allow Intelligence to carry out the investigation.

Torres' personal involvement with an informant jeopardizes his safety and threatens to expose an undercover operation.

Intelligence chases down a lead in the ongoing serial killer investigation as news of the case reaches the public.