After a slew of brutal slayings, District 21, led by Sergeant Hank Voight go after a Columbian drug cartel cleaning house in Chicago. They discover D’Anthony who proves to be an asset in the investigation. At District, complicated histories and unit rivalries surface which could end up costing them one of their own. Meanwhile, Rookie Kyle Ruzek is pulled from the police academy by Olinski to join the team.

Antonio’s son was kidnapped and he has a feeling the Columbian drug gang is to blame. Pulpo, the Columbian gang leader, is being held in jail and suggests his release may trigger the release of Diego. During the investigation, Halstead learns some new information about Lindsay. Voight offers Antonio a new approach to get information on Diego’s whereabouts.

Voight and team head to a house that’s been associated with a number of top gangs. Events at the search result in Ruzek, being encouraged to seek some counseling which may have lasting repercussions professionally and personally. Meanwhile Halstead’s temper rises when he comes in contact with some unwelcomed people from his past.

More is learned about Halstead’s dislike of the Rodiger family and it’s family relationships all around as Olinsky shows a paternal side with his daughter Lexi in an attempt to protect her and as Voight’s trying to help his son who has recently been released from jail. Meanwhile the Intelligence Unit investigates a counterfeiting operation after discovering some high end cloth-like paper. Sergeant Platt sends Atwater and Burgess to arrest a hoarder where they discover more than just clutter.

Atwater and Burgess are given a new patrol car, but are challenged with keeping it brand new. A run in with a psychotic woman leads the Intelligence Unit to discover a drug smuggling operation which has put several girl’s lives in peril. Voight’s overprotective act with Lindsay leads her right where he doesn’t want as she also helps to keep Justin out of trouble. Meanwhile on stakeout, things get tense between Olinsky and Ruzek as Olinski tries to teach him the finer points of surveillance.

Voight and Antonio enlist the help of agents at the Special Victims Unit in New York, Fin and Rollins, to help track down the culprit of a series of rape/murders. Burgess has an opportunity to prove herself to Intelligence. Elsewhere Lindsay enlists the help of Halstead to act as her date for her high school reunion to get back at an old rival.

The crossover starts on Law & Order: Special Victims Unit S15E15 Comic Perversion (I).

Voight's son may be involved with the Fitori murder case, intensifying tension between Antonio and Voight; Ruzek helps Burgess get retribution.

Voight is assigned a new Internal Affairs handler, Stillwell who proves to be suspicious of Voight’s actions. During an investigation involving a gambling ring Voight is forced to work with his former partner from the Gang Unit, Shi. At the same time Halsted remains fixated on Lonnie Rodiger and enlists Jin’s help to gather more information. Meanwhile, Ruzek’s inflated ego leads Olinsky to take him down a peg and offer a great opportunity to Atwater.

In responding to a call Atwater and Burgess discover a gunshot victim and the only witness is Lexi Olinsky. The shooting is tied to a Latin gang. To protect Olinsky’s daughter, Voight takes the case from the Gang Unit. Ruzek pulls up Burgess to help with an undercover mission that he hopes will help solve the case. Jon Seda, Sophia Bush, Jesse Lee Soffer, and Archie Kao also star.

Halstead's badge is revoked when Lonnie Rodiger is found dead; Severide and Clarke find Dr. Elliot's torso; Sumner tries to prove herself; Lindsay shares a moment with Severide.

Voight and the team discover a massacre, eight million in cash stolen and two wounded men in a clearing house. During questioning, one guy, Perko, provides some intel that is key to the case and leads Antonio to realize that two gangs were involved. Burgess steps up to help the unit and prove herself to Voight. Meanwhile, a softer light is cast on Platt when she enlists the help of Ruzek.

The Intelligence Unit works to find the bombers. Even with government agencies in the mix, Voight and his team work the case from their own angles and connections. Lindsay and Antonio question doctors who handled the transplant surgery for an Ambassador from Syria, but no clues emerge. Olinsky gets some solid intel and the team work from there. It’s a race against time as they realize there may be additional bombs targeted to detonate. Meanwhile Burgess sits vigil for her niece whose life hangs in the balance.

The crossover starts on Chicago Fire S02E20 A Dark Day (I).

Commander Perry notifies the Intelligence unit that Pulpo has been released to help track down a dangerous cartel leader. This doesn’t sit well with our team as he kidnapped one of their own and no love is lost between sides. Meanwhile, Ruzek gets some difficult news as a blast from Lindsay’s past comes back, giving us a glimpse at where she came from. Voight reminds her that she’s come too far to screw it up. At the same time we learn something about Jin that is bound to be a problem.

As Antonio’s life is now in question, Voight and Platt open up about their pasts. Jin is caught while tinkering with Voight’s computer and uses the only scapegoat possible to keep him in the clear. At the same time with Charlie back in town Lindsay realizes she’s going to have to come clean about a few things. Halstead finally gets answers he’s been wanting about Voight’s and Olinsky’s past.

Atwater is settling into his new gig on intelligence as Antonio is relegated to desk duty while recovering. Lindsay finally realizes she has no way out and confides in Voight for help. Meanwhile Jin is confronted about his secret meetings with Stillwell.

As the Sheldon Jin murder investigation moves forward, Voight is under close watch by Internal Affairs but he’s still in complete command of the intelligence unit. A routine undercover job becomes anything but when Voight’s SUV is T-boned while trailing an armored car carrying Ruzek. Burgess meets her new partner, Sean Roman and tension is high from the start, and she soon realizes there’s more to his story. After a long day, Lindsay pays a visit to someone she hasn’t seen in a very long time.

Intelligence begins to look into a string of murders where the victims have a dollar bill pinned to their chests. Thanks to some digging by Ruzek, Voight learns his friend was involved in some shady business dealings. Antonio and Halstead follow-up on some leads that help focus in on the culprit and motives for the murders. Burgess and Roman investigate a series of house break-ins and get some help from Desk Sgt. Platt.

The bounty on Halstead’s head becomes a serious reality as an innocent bartender takes a bullet meant for him. Olinsky tries to reason with Bembenek to call off the hit. Voight and the team keep this investigation in-house to find the hired assassin. After a tense interaction at district, Platt and Nadia come to an understanding.

Two teenage girls have gone missing and the team know the clock is ticking to find them. Halstead, Antonio and Lindsay investigate a tenement which gives them a much needed lead. Voight brings the father of one of the girls to district in order to get some honest answers. Platt puts Roman and Burgess on gun buy-back duty where they ask questions when they aren’t supposed to.

While trying to help out, Olive Voight is attacked and taken. Ruzek and Atwater prove they belong on the team when they demonstrate smarts and savvy tracking down a lead that will hopefully bring them to Voight. Burgess and Roman try to track down a girl who runs off with a police badge.

Following the death of a 10-year old girl, the intelligence unit has one option to gain access to their suspect. Voight and Olinsky follow-up on a good lead to answer some questions about the shooting. Burgess and Roman show three boys around district thinking they are part of the Police Explorers program.

The intelligence unit is joined by detectives from New York’s SVU to help solve the pedophile ring case. Ruzek, Amaro, Halstead and Antonio continue to hunt for the link to foster care and child trafficking. Burgess and Roman try to find the shooter from the hospital after using surveillance footage to identify him. Platt shows her deep respect for police and the dangerous work they do by honoring their fallen brother.

The crossover starts on Chicago Fire S03E07 Nobody Touches Anything (I) and Law & Order: Special Victims Unit S16E07 Chicago Crossover (II).

While Antonio continues his off-duty security job for Asher and Layla, Asher is killed. While they work the case, Halstead and Lindsay go undercover in a rather uncomfortable location. Kot shows up to ask Lindsay for an answer.

A friend of Nadia’s leads the intelligence unit to a huge heroin bust. Unfortunately this bust results in Olinsky arriving home to find the suspects are holding his wife. Voight and the team think they’ve found a common thread with the suspects but it’s not who they think. Meanwhile Burgess and Roman are given an assignment where they get paired with a K-9 officer, Jenn Cassidy who is Roman’s former partner and girlfriend.

With Burgess in the hospital after suffering gunshot wounds, the intelligence team is determined to find the people responsible. Lindsay delays her start on the federal task force so she can help with this case. Search of the house provides a lead and when a bomb is triggered a key suspect is found. Meanwhile the team takes turns watching over Burgess. Voight informs Burgess of a new opportunity that this affords her.

Lindsay has her first case with the task force and realizes she needs to call on Voight and the Intelligence unit to assist. Meanwhile Burgess is back on the job, but relegated to desk duty which allows Desk Sgt. Platt the opportunity to partner up with Roman.

Bob Ruzek is the first to arrive on the scene of a double murder. Intelligence arrives to take over the investigation and tensions arise as Bob needs to hand over the case to his son and Voight. Lindsay's new gig has her planning a trip to Bolivia for an undercover investigation that could be for an extended amount of time. Burgess and Roman realize they need to put past events behind them so it doesn't jeopardize them going forward.

Antonio and his sister Gabriela go to the office of Elliot Gish, the man they believe started the fire that killed Shay. Intelligence, along with patrol officers Burgess and Roman, put pressure on Gish to confess. Lindsay approaches Voight about returning to Intelligence when she realizes that the task force isn’t what she thought it would be. Desk Sgt. Platt has everyone curious why she’s being overly cheery, friendly and nice.

The crossover starts on Chicago Fire S03E13 Three Bells (I).

Bunny comes to Lindsay concerned about a suspicious repeat customer at her husband’s rental company. This lead brings Intelligence into a case which robbery-homicide has been working for months.

Burgess begins to regret her recent decision to stay on the beat. While at a convenience store she sees some suspicious activity and pursues it without calling in for backup. It's a slow day in Intelligence as they spend their time receiving taser certification.

Antonio heads undercover with a dangerous robbery crew after a narcotics officer goes missing.

When a murder implicates a diplomat, the FBI stands between Intelligence and justice.

When Voight's card ends up in the hands of a murder suspect, he aims to protect the man at any cost.

Led by Olinksy, Intelligence hunts down an elusive Chinatown gangster.

SVU's Benson, Fin and Amaro help with the investigation of a rape-murder that's similar to a decade-old case in New York; and, after he's questioned, a suspect warns Lindsay that the investigation could have unintended consequences.

The crossover starts on Chicago Fire S03E21 We Called Her Jellybean (I). It continues on Law & Order: Special Victims Unit S16E20 Daydream Believer (III).

The investigation into the bombing of a trendy café hinges on a minor who witnessed it. A major blunder lands Atwater in hot water. Voight helps Platt in her attempt to get a memorial stone for the team's fallen member.

A mass shooting at an athletic club is investigated; and Atwater, who's dealing with his new assignment, helps locate the suspected shooters. Platt and Halstead, meanwhile, check in with Lindsay to see how she's managing.

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.