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 dangerous South Side 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 in his court case.

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 undercover to Intelligence.

After zeroing in on the suspect responsible for the bioterrorism that’s gripping Chicago, the PD prepares to undertake their biggest manhunt yet. Upton is torn between helping track down the perp and providing emotional support to the scared young girl that needs her. Voight fears his team is being sent on a wild goose chase.

The crossover starts on Chicago Fire S08E04 Infection (I) and Chicago Med S05E04 Infection, Part II (II).

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.

The shocking murder of young boys affects Halstead. Crawford encourages Intelligence to use a new facial-recognition software to help identify a suspect, but the plan backfires.

Voight pulls Darius in after Crawford asks Intelligence to investigate a dangerous drug, but there is little trust in the relationship. When their plan to nail a dealer goes awry and another CI is murdered, the team must make a tough decision about Darius.

After injuring herself while pursuing a suspect, Burgess receives a shocking diagnosis. A homicide case turns into a missing persons case, with a sinister twist. Voight has to decide between justice and the letter of the law.

Halstead's secret ongoing relationship with a woman connected to another case puts him in jeopardy.

As they await news of Halstead’s fate, the team tries to focus on work, turning their attention to an illegal arms dealer. Atwater discovers his brother, Jordan, is back in Chicago and could be tied to the case. Voight faces the tricky task of how to deal with Halstead’s shooter. Burgess finally makes her decision.

Ruzek and Burgess’s secret begins to have severe implications for their police work. A series of deadly acts of vandalism causes tensions to run high in the insular neighborhood of Canaryville. Atwater tries to reach out to his brother, but only pushes him further away.

Voight makes a deal with Darius Walker to help bring down a rogue group of dirty cops dealing drugs that were supposed to be destroyed. Upton clashes with Voight and enacts her own form of justice.

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

A homeless man's murder leads Intelligence to a criminal who has evaded capture for years. Rojas has a troubling experience with a young mentally ill man.

Intelligence searches for the dealer who caused multiple overdoses and is connected to Roman's missing sister. The case becomes a homicide investigation when they find the dealer's dead body.

The crossover starts on Chicago Fire S08E15 Off the Grid (I).

An armed robbery case quickly turns into a homicide investigation. When one suspect’s background suggests domestic violence, Upton is forced to reckon with her childhood. Voight and Halstead butt heads over Halstead’s righteous instinct.

Voight enlists the help of a reformed gang member to get a key witness' testimony in a murder case. More lives are put on the line as a gang war brews.

Intelligence does everything they can to build a case against the elusive leader of a drug ring, but things get complicated when Rojas realizes someone she cares about might be involved.

The clock is on after Ruzek witnesses a woman's kidnapping and the team races to put the pieces together. Burgess tries to connect with Ruzek outside of work but he mysteriously distances himself from her.

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

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.

When the son of an influential former officer is implicated in a murder, Moore pressures Voight to charge him quickly. The stakes are raised in Atwater's fight against the blue wall after patrol officers stop responding to his team's calls.

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.

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.

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.

Halstead and Ruzek try to infiltrate a crime ring and encounter a complicated situation. The team recruits an unlikely ally to help solve a murder.

After a series of deadly ambushes, the team goes undercover to bring down a dangerous new drug dealer who is determined to push out the competition. Ruzek's informant proves to be a loose cannon that could upset the whole operation.

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.

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.

Ruzek's father, Bob, 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.

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

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.

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

Voight and the team pursue a ruthless crime ring whose business has hit close to home. As they dig deeper, the extent of the danger becomes more apparent. Deputy Superintendent Samantha Miller second-guesses her decisions.

Voight and the team muster all their expertise to bring down a deadly crime ring. Burgess finds herself in a dangerous situation.

When a P.D. informant is murdered, the team digs in to track down the perpetrator only to learn a shocking truth. Voight and Ruzek strategize to help Burgess.

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.

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.

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

As the team works to solve a deadly shooting in Burnside, Atwater realizes he has a very personal connection to the case.

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.

As the team works to bring down a drug ring, Voight builds trust with a new informant. However, it soon becomes clear she has a plan of her own.

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.

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.

The team searches for a missing child in what turns out to be a very complicated case. Burgess and Ruzek are in for a shock when someone from Makayla’s past comes forward.

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.

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.

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.

The team searches for a brutal killer with a signature modus operandi. Burgess and Ruzek double down in their fight to retain custody of Makayla.

The unit scrambles to search for one of their own who is in grave danger.

When a young man is shot outside the Cárabo Bakery, the team works to connect the shooting to bakery owner Javier Escano, who has been under surveillance. Despite the increasing danger, Voight helps informant Anna Avalos get even closer to their target.

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.

Halstead takes a new recruit under his wing during an investigation. The dynamics are challenging, however, and questions arise over the recruit's complicated past.

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.

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.

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.

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.

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.

The team investigates a string of brutal pharmacy robberies, and Halstead connects with one of the victims about their Army careers. Upton suspects there is more to the story and confides in Voight.

A shocking murder pulls rookie officer Dante Torres into his own neighborhood. As Voight and Atwater help him navigate the case and manage tricky personal dynamics with wary neighbors, Torres realizes his life may be forever changed.

Upton's dogged pursuit of a missing teenage girl leads the team into a dark web of human trafficking. Chief O'Neal becomes involved with the unit's investigation when it becomes evident his son, Sean, has a connection to the missing girl.

Atwater’s reactions during a tense arrest are called into question. The team must dig in to uncover key evidence that could aid in the ongoing investigation and clear Atwater’s name.

When actionable evidence finally surfaces against Sean O'Neal, Upton and the team work relentlessly to build a case in secret. They discover Sean is more elusive and dangerous than anticipated.

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.

After a shocking discovery, the team begins closing in on Sean O’Neal with every shred of evidence they can find. Determined to keep his son out of prison, Chief O’Neal hires a lawyer.

A series of brutal home invasion robberies finds the team paired with Detective Borkowski, an old friend of Ruzek's, to work the case. Things get complicated for Torres when it becomes clear Borkowski has a vastly different policing style.

A shocking ambush at a funeral leads the team into a heated investigation to find the shooters. Much to Atwater's surprise, he must rely on someone from his past to help in the investigation, dredging up old memories and revealing new truths.

Sean O'Neal surprises Upton with a call from prison, revealing sensitive information. Meanwhile, the team quickly mobilizes to stop a crime in progress before it's too late.

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.

After a brutal shooting, Burgess and Ruzek find themselves trapped aboard the busy "L" subway. As they piece together scant evidence, the team is drawn into a dark family drama.

When a family is poisoned in their home, the team discovers a connection to the Becks. Ruzek goes undercover to work for their business, and as he gets closer to Samantha, chilling information about her father, Richard, comes to light.

Voight takes the stand in a high-stakes murder trial against notorious drug kingpin Arturo Morales. When it becomes clear that Morales and his henchmen have compromised a juror, Voight and the team work furiously to ensure justice prevails.

As the team investigates a convenience store robbery, the evidence leads them to an unusual pair of suspects, revealing a dark personal drama and another potential victim. Burgess slowly makes strides tackling her past trauma.

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.

Atwater's worlds collide when a shooting at the building he owns in Burnside leaves a child dead. Atwater must confront his relationship with his father, Lew, as the brutal case forces them together.

Upton is unwittingly drawn into a deadly betrayal and finds herself in a fight for her life. With minimal leads, Voight and the team scramble to find her before it's too late.

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.

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.