Casey reunites with a former colleague; Dawson and Brett serve their time in retraining; Severide tries to fix what's going on with Anna.

Chief Anderson feels his authority was undercut after Chief Boden makes a decision that overrides Anderson's when both squads respond to the scene of a dangerous accident; Severide ponders a lifechanging decision; Herrmann does a good deed.

When a man moves to Canyon Country, Calif., he finds himself embroiled in a bizarre and increasingly acrimonious 8-year feud with a neighbor that terminates with blasts from a shotgun.

Traci worries that she mishandled the investigation into a car accident that yielded a dead body; Chris realizes he has feelings for Gail.

The CEO of a mortgage company is taken hostage by three men; the team reluctantly looks for recruits to fill Jules' spot.

When a man moves to Canyon Country, Calif., he finds himself embroiled in a bizarre and increasingly acrimonious 8-year feud with a neighbor that terminates with blasts from a shotgun.

Traci worries that she mishandled the investigation into a car accident that yielded a dead body; Chris realizes he has feelings for Gail.

The CEO of a mortgage company is taken hostage by three men; the team reluctantly looks for recruits to fill Jules' spot.

When a man moves to Canyon Country, Calif., he finds himself embroiled in a bizarre and increasingly acrimonious 8-year feud with a neighbor that terminates with blasts from a shotgun.

Traci worries that she mishandled the investigation into a car accident that yielded a dead body; Chris realizes he has feelings for Gail.

The CEO of a mortgage company is taken hostage by three men; the team reluctantly looks for recruits to fill Jules' spot.

Will confronts a moral decision when his former teacher faces a life-threatening disease; Rhodes disagrees with the father of a young patient about a risky procedure; an unusual case causes Sarah to recall Jason Wheeler's suicide.

Doctors must diagnose patients without the aid of technology after a hacker shuts down the hospital computer system; Goodwin gets a visit from her ex husband Bert and his new girlfriend; Choi and Noah have to remove a bullet from a gunshot victim.

Dr. Halstead's father is admitted to the hospital against his wishes; Dr. Charles gets involved when his daughter's strange behavior continues to intensify; Dr. Manning feels the impact of being a working mother.

A mother is desperate to help her daughter beat cancer; Dr. Charles asks Sarah to conduct his daughter Robin's psych evaluation; Dr. Choi puts pressure on Noah when a residency spot becomes available.

Dr. Rhodes challenges Dr. Charles and other hospital staff over treatment for Robin; Dr. Manning seeks help from Detective Halstead when a sensitive case involving a young girl turns into a crime; Goodwin helps a friend in distress.

An audacious new doctor arrives at Chicago Med; Dr. Halstead and Dr. Manning team up to diagnose a Syrian refugee who has no medical record; Robin is admitted back into the hospital; Noah hosts a graduation party.

The doctors of Chicago Med try to bring justice to the perpetrator in the shooting of Dr. Charles; Robin is discharged from the rehabilitation center, but Dr. Rhodes worries that her problems are not quite resolved; Maggie sticks up for a patient.

Will confronts a moral decision when his former teacher faces a life-threatening disease; Rhodes disagrees with the father of a young patient about a risky procedure; an unusual case causes Sarah to recall Jason Wheeler's suicide.

Doctors must diagnose patients without the aid of technology after a hacker shuts down the hospital computer system; Goodwin gets a visit from her ex husband Bert and his new girlfriend; Choi and Noah have to remove a bullet from a gunshot victim.

Dr. Halstead's father is admitted to the hospital against his wishes; Dr. Charles gets involved when his daughter's strange behavior continues to intensify; Dr. Manning feels the impact of being a working mother.

A mother is desperate to help her daughter beat cancer; Dr. Charles asks Sarah to conduct his daughter Robin's psych evaluation; Dr. Choi puts pressure on Noah when a residency spot becomes available.

Dr. Rhodes challenges Dr. Charles and other hospital staff over treatment for Robin; Dr. Manning seeks help from Detective Halstead when a sensitive case involving a young girl turns into a crime; Goodwin helps a friend in distress.

An audacious new doctor arrives at Chicago Med; Dr. Halstead and Dr. Manning team up to diagnose a Syrian refugee who has no medical record; Robin is admitted back into the hospital; Noah hosts a graduation party.

The doctors of Chicago Med try to bring justice to the perpetrator in the shooting of Dr. Charles; Robin is discharged from the rehabilitation center, but Dr. Rhodes worries that her problems are not quite resolved; Maggie sticks up for a patient.

Will confronts a moral decision when his former teacher faces a life-threatening disease; Rhodes disagrees with the father of a young patient about a risky procedure; an unusual case causes Sarah to recall Jason Wheeler's suicide.

A family moves into a Minnesota lake house, then a dispute with a neighbor over water access escalates until it leads to a bloody resolution.

Andy answers a domestic disturbance call to find the social worker on the scene is her estranged mother; Sam, Nick, Chris and Gail search for a mother and her two children; a stash of guns recovered by Detective Barber turns up on the streets.

The SRU is called to what appears to be a home invasion turned into a standoff, but team members soon realize the hostage-taker is no stranger to the family.

A family moves into a Minnesota lake house, then a dispute with a neighbor over water access escalates until it leads to a bloody resolution.

Andy answers a domestic disturbance call to find the social worker on the scene is her estranged mother; Sam, Nick, Chris and Gail search for a mother and her two children; a stash of guns recovered by Detective Barber turns up on the streets.

The SRU is called to what appears to be a home invasion turned into a standoff, but team members soon realize the hostage-taker is no stranger to the family.

A family moves into a Minnesota lake house, then a dispute with a neighbor over water access escalates until it leads to a bloody resolution.

Andy answers a domestic disturbance call to find the social worker on the scene is her estranged mother; Sam, Nick, Chris and Gail search for a mother and her two children; a stash of guns recovered by Detective Barber turns up on the streets.

The SRU is called to what appears to be a home invasion turned into a standoff, but team members soon realize the hostage-taker is no stranger to the family.

The 118 responds to calls dealing with parents and their children, including a disastrous birthday party thrown by a mommy blogger; Athena and Michael talk to May about her past suicide attempt; Chimney and Maddie adjust to life with their newborn.

The members of the 118 rush to the site of a hit-and-run that leaves a familiar face in critical condition; with Buck's help, Athena investigates the case of a missing woman; Josh recalls an emergency in 2006 that led him to become a first responder.

When a famous mystery writer dies, Athena, Bobby and the 118 respond to the chaos caused by a citywide manhunt for buried treasure the author left behind.

The members of the 118 make calls to save a bridezilla at a disastrous wedding; Hen plays medical detective when her mother falls ill; Eddie and Christopher receive a visit from Carla; Athena uncovers a secret Bobby has been hiding.

Athena and the 118 are on high alert when a sniper is targeting members of the LAFD; Maddie makes a life decision.

A series of ransomware threats leads to emergencies for the 118, including a helicopter crash at a hospital and an air traffic control tower system failure; the case of the realtor serial rapist goes to trial.

The 118 springs into action when a citywide blackout and a record heat wave causes mayhem in Los Angeles; Chimney confides in Hen about Maddie's condition; Athena's worst nightmare comes true.

The 118 responds to calls dealing with parents and their children, including a disastrous birthday party thrown by a mommy blogger; Athena and Michael talk to May about her past suicide attempt; Chimney and Maddie adjust to life with their newborn.

The members of the 118 rush to the site of a hit-and-run that leaves a familiar face in critical condition; with Buck's help, Athena investigates the case of a missing woman; Josh recalls an emergency in 2006 that led him to become a first responder.

When a famous mystery writer dies, Athena, Bobby and the 118 respond to the chaos caused by a citywide manhunt for buried treasure the author left behind.

The members of the 118 make calls to save a bridezilla at a disastrous wedding; Hen plays medical detective when her mother falls ill; Eddie and Christopher receive a visit from Carla; Athena uncovers a secret Bobby has been hiding.

Athena and the 118 are on high alert when a sniper is targeting members of the LAFD; Maddie makes a life decision.

A series of ransomware threats leads to emergencies for the 118, including a helicopter crash at a hospital and an air traffic control tower system failure; the case of the realtor serial rapist goes to trial.

The 118 springs into action when a citywide blackout and a record heat wave causes mayhem in Los Angeles; Chimney confides in Hen about Maddie's condition; Athena's worst nightmare comes true.

The 118 responds to calls dealing with parents and their children, including a disastrous birthday party thrown by a mommy blogger; Athena and Michael talk to May about her past suicide attempt; Chimney and Maddie adjust to life with their newborn.

In Elyria, Ohio, two neighboring families live in harmony for decades, then their friendly coexistence devolves into acrimony, accusations and violence.

Oliver Shaw's teenage daughter, Izzy, witnesses the brutal stabbing of a homeless squatter; when Izzy goes missing, officers rush to track her down.

The team discovers that the federal agent they are working with during the transport of a serial killer is secretly sabotaging their mission.

In Elyria, Ohio, two neighboring families live in harmony for decades, then their friendly coexistence devolves into acrimony, accusations and violence.

Oliver Shaw's teenage daughter, Izzy, witnesses the brutal stabbing of a homeless squatter; when Izzy goes missing, officers rush to track her down.

The team discovers that the federal agent they are working with during the transport of a serial killer is secretly sabotaging their mission.

In Elyria, Ohio, two neighboring families live in harmony for decades, then their friendly coexistence devolves into acrimony, accusations and violence.

Oliver Shaw's teenage daughter, Izzy, witnesses the brutal stabbing of a homeless squatter; when Izzy goes missing, officers rush to track her down.

The team discovers that the federal agent they are working with during the transport of a serial killer is secretly sabotaging their mission.

Dr. Manning goes to extreme measures to help a fearful pregnant woman; Dr. Choi and April try to strike a balance at work; Dr. Charles and Dr. Reese continue to disagree about their patients.

Goodwin is forced by the hospital board to implement new guidelines that cause headaches for the doctors; Dr. Rhodes and Ava continue to compete in the operating room; Dr. Charles and Dr. Reese are surprised by a patient's theory about his sickness.

Dr. Charles learns a troubling fact about the man who shot him; Dr. Rhodes and Dr. Bekker come to an agreement during a complicated surgery; Will and Natalie have an ethical dilemma; April and Noah discover working together isn't always easy.

An ethical debate arises when a patient refuses to take an HIV test but still demands treatment; Natalie and Will try to diagnose a young girl with increasing paralysis; Noah deals with his first death as a resident; Sarah continues to avoid work.

Ethan tries to diagnose a man with no symptoms; Sarah uses pepper spray on an aggressive patient; Will treats a young couple willing to sacrifice anything to have a baby; Natalie must inform a woman that she was sterilized as a young girl.

Dr. Charles is pressured when Dr. Choi and Dr. Manning disagree with his medical decision regarding a baby born with an addiction to heroin; Dr. Rhodes deals with relationship issues; Goodwin helps Bert understand Lyla's sickness.

Dr. Choi struggles to help a woman cope with anorexia; after a suspension, Dr. Reese is immediately put to the test by Dr. Charles; a patient of Dr. Rhodes' is forcibly transferred; Dr. Halstead tries to get Dr. Manning's son to like him.

Dr. Manning goes to extreme measures to help a fearful pregnant woman; Dr. Choi and April try to strike a balance at work; Dr. Charles and Dr. Reese continue to disagree about their patients.

Goodwin is forced by the hospital board to implement new guidelines that cause headaches for the doctors; Dr. Rhodes and Ava continue to compete in the operating room; Dr. Charles and Dr. Reese are surprised by a patient's theory about his sickness.

Dr. Charles learns a troubling fact about the man who shot him; Dr. Rhodes and Dr. Bekker come to an agreement during a complicated surgery; Will and Natalie have an ethical dilemma; April and Noah discover working together isn't always easy.

An ethical debate arises when a patient refuses to take an HIV test but still demands treatment; Natalie and Will try to diagnose a young girl with increasing paralysis; Noah deals with his first death as a resident; Sarah continues to avoid work.

Ethan tries to diagnose a man with no symptoms; Sarah uses pepper spray on an aggressive patient; Will treats a young couple willing to sacrifice anything to have a baby; Natalie must inform a woman that she was sterilized as a young girl.

Dr. Charles is pressured when Dr. Choi and Dr. Manning disagree with his medical decision regarding a baby born with an addiction to heroin; Dr. Rhodes deals with relationship issues; Goodwin helps Bert understand Lyla's sickness.

Dr. Choi struggles to help a woman cope with anorexia; after a suspension, Dr. Reese is immediately put to the test by Dr. Charles; a patient of Dr. Rhodes' is forcibly transferred; Dr. Halstead tries to get Dr. Manning's son to like him.

Dr. Manning goes to extreme measures to help a fearful pregnant woman; Dr. Choi and April try to strike a balance at work; Dr. Charles and Dr. Reese continue to disagree about their patients.

When District 21 goes after a Colombian drug gang following a series of brutal slayings, an asset in the investigation emerges.

Antonio believes a Colombian gang is involved in his son's kidnapping; Halstead learns new information about Lindsay; Voight offers Antonio a new way to get information about Diego's whereabouts.

Voight and the team check out a house that has been associated with a series of gangs; people from the past cause Halstead's temper to rise.

Olinsky tries to protect his daughter; a counterfeiting operation is investigated; when a hoarder is arrested, more than clutter is uncovered.

Atwater and Burgess must keep their new patrol car in mint condition; the Intelligence Unit uncovers drug smuggling; Voight's behavior toward Lindsay drives her right where he doesn't want her; tensions rise between Olinsky and Ruzek.

New York's SVU agents Fin and Rollins help track down a serial killer who rapes his victims; Burgess gets an opportunity to prove herself; Lindsay brings Halstead as her date to her high school reunion.

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

When District 21 goes after a Colombian drug gang following a series of brutal slayings, an asset in the investigation emerges.

Antonio believes a Colombian gang is involved in his son's kidnapping; Halstead learns new information about Lindsay; Voight offers Antonio a new way to get information about Diego's whereabouts.

Voight and the team check out a house that has been associated with a series of gangs; people from the past cause Halstead's temper to rise.

Olinsky tries to protect his daughter; a counterfeiting operation is investigated; when a hoarder is arrested, more than clutter is uncovered.

Atwater and Burgess must keep their new patrol car in mint condition; the Intelligence Unit uncovers drug smuggling; Voight's behavior toward Lindsay drives her right where he doesn't want her; tensions rise between Olinsky and Ruzek.

New York's SVU agents Fin and Rollins help track down a serial killer who rapes his victims; Burgess gets an opportunity to prove herself; Lindsay brings Halstead as her date to her high school reunion.

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

A Chinese maintenance man (Jackie Chan) instructs an American boy (Jaden Smith) in the art of kung fu to help the youth face down bullies at his new school.

When District 21 goes after a Colombian drug gang following a series of brutal slayings, an asset in the investigation emerges.

Antonio believes a Colombian gang is involved in his son's kidnapping; Halstead learns new information about Lindsay; Voight offers Antonio a new way to get information about Diego's whereabouts.

Voight and the team check out a house that has been associated with a series of gangs; people from the past cause Halstead's temper to rise.

Olinsky tries to protect his daughter; a counterfeiting operation is investigated; when a hoarder is arrested, more than clutter is uncovered.

Atwater and Burgess must keep their new patrol car in mint condition; the Intelligence Unit uncovers drug smuggling; Voight's behavior toward Lindsay drives her right where he doesn't want her; tensions rise between Olinsky and Ruzek.

New York's SVU agents Fin and Rollins help track down a serial killer who rapes his victims; Burgess gets an opportunity to prove herself; Lindsay brings Halstead as her date to her high school reunion.

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

Voight's new Internal Affairs handler proves to be suspicious of his actions; Voight must work with his former partner from the Gang Unit; Halsted enlists Jin to help him gather more information on Lonnie Rodiger; Olinsky takes Ruzek down a peg.

Burgess and Atwater come across a gunshot victim and the only witness is Olinsky's daughter; Ruzek goes to Burgess for help with an undercover mission.

Halstead's badge is revoked when Lonnie Rodiger is found dead; Severide (Taylor Kinney) and Clarke (Peter Mills) find Dr. Elliot's torso; Sumner (Sydney Tamiia Poitier) tries to prove herself; Lindsay shares a moment with Severide.

Dueling gangs are suspected when a massacre occurs and $8 million is stolen; Platt asks Ruzek for help.

As Voight and his team search for the bombers, they realize there might be more bombs set to detonate; Burgess' niece fights for her life.

Cmdr. Perry notifies the unit that Pulpo has been released to help with a case; Ruzek gets difficult news; when a bit of Lindsay's past resurfaces, Voight reminds her how far she's come.

Platt and Voight discuss their pasts; Jin uses a scapegoat when he is caught tinkering with Voight's computer; Lindsay realizes she needs to come clean.

Voight's new Internal Affairs handler proves to be suspicious of his actions; Voight must work with his former partner from the Gang Unit; Halsted enlists Jin to help him gather more information on Lonnie Rodiger; Olinsky takes Ruzek down a peg.

Burgess and Atwater come across a gunshot victim and the only witness is Olinsky's daughter; Ruzek goes to Burgess for help with an undercover mission.

Halstead's badge is revoked when Lonnie Rodiger is found dead; Severide (Taylor Kinney) and Clarke (Peter Mills) find Dr. Elliot's torso; Sumner (Sydney Tamiia Poitier) tries to prove herself; Lindsay shares a moment with Severide.

Dueling gangs are suspected when a massacre occurs and $8 million is stolen; Platt asks Ruzek for help.

As Voight and his team search for the bombers, they realize there might be more bombs set to detonate; Burgess' niece fights for her life.

Cmdr. Perry notifies the unit that Pulpo has been released to help with a case; Ruzek gets difficult news; when a bit of Lindsay's past resurfaces, Voight reminds her how far she's come.

Platt and Voight discuss their pasts; Jin uses a scapegoat when he is caught tinkering with Voight's computer; Lindsay realizes she needs to come clean.

Lawyer Bryan Stevenson takes on the case of Walter McMillian, who is sentenced to die for murder despite evidence proving his innocence. In the years that follow, Stevenson encounters racism and legal maneuverings as he fights for McMillian's life.

Voight's new Internal Affairs handler proves to be suspicious of his actions; Voight must work with his former partner from the Gang Unit; Halsted enlists Jin to help him gather more information on Lonnie Rodiger; Olinsky takes Ruzek down a peg.

Burgess and Atwater come across a gunshot victim and the only witness is Olinsky's daughter; Ruzek goes to Burgess for help with an undercover mission.

Halstead's badge is revoked when Lonnie Rodiger is found dead; Severide (Taylor Kinney) and Clarke (Peter Mills) find Dr. Elliot's torso; Sumner (Sydney Tamiia Poitier) tries to prove herself; Lindsay shares a moment with Severide.

Dueling gangs are suspected when a massacre occurs and $8 million is stolen; Platt asks Ruzek for help.

As Voight and his team search for the bombers, they realize there might be more bombs set to detonate; Burgess' niece fights for her life.

Cmdr. Perry notifies the unit that Pulpo has been released to help with a case; Ruzek gets difficult news; when a bit of Lindsay's past resurfaces, Voight reminds her how far she's come.

Platt and Voight discuss their pasts; Jin uses a scapegoat when he is caught tinkering with Voight's computer; Lindsay realizes she needs to come clean.

Atwater settles into his new role; Lindsay turns to Voight for help; Jin is confronted about his meetings with Stillwell.

As the Sheldon Jin investigation moves forward, Internal Affairs keeps a close eye on Voight; Voight's vehicle is T-boned while following an armored car carrying Ruzek; Burgess meets her new partner; Lindsay visits her mom.

Several murder victims are found with a dollar bill pinned to their chests; Voight makes a discovery about a friend; a series of home invasions.

When a bartender takes a bullet intended for Halstead, the bounty on him becomes more real; following a tense interaction, Platt and Nadia reach an understanding.

The team races against the clock when two teenage girls disappear; Voight seeks honest answers from the father of one of the girls.

Voight is attacked and abducted while trying to help Olive; Roman and Burgess search for a girl who has taken off with a police badge.

Ruzek and Atwater go under cover as prison inmates in order to find the man they believe killed a 10-year-old girl; Burgess and Roman give a tour of the district to some boys they believe are part of the Police Explorers program.

Detectives from New York's SVU come to Chicago to help take down a pedophilia ring; Platt shows her respect for the police.

Atwater settles into his new role; Lindsay turns to Voight for help; Jin is confronted about his meetings with Stillwell.

As the Sheldon Jin investigation moves forward, Internal Affairs keeps a close eye on Voight; Voight's vehicle is T-boned while following an armored car carrying Ruzek; Burgess meets her new partner; Lindsay visits her mom.

Several murder victims are found with a dollar bill pinned to their chests; Voight makes a discovery about a friend; a series of home invasions.

When a bartender takes a bullet intended for Halstead, the bounty on him becomes more real; following a tense interaction, Platt and Nadia reach an understanding.

The team races against the clock when two teenage girls disappear; Voight seeks honest answers from the father of one of the girls.

Voight is attacked and abducted while trying to help Olive; Roman and Burgess search for a girl who has taken off with a police badge.

Aquaman must retrieve the legendary Trident of Atlan to save the underwater city of Atlantis -- and the surface world -- from his power-hungry brother.

As the Sheldon Jin investigation moves forward, Internal Affairs keeps a close eye on Voight; Voight's vehicle is T-boned while following an armored car carrying Ruzek; Burgess meets her new partner; Lindsay visits her mom.

Several murder victims are found with a dollar bill pinned to their chests; Voight makes a discovery about a friend; a series of home invasions.

When a bartender takes a bullet intended for Halstead, the bounty on him becomes more real; following a tense interaction, Platt and Nadia reach an understanding.

The team races against the clock when two teenage girls disappear; Voight seeks honest answers from the father of one of the girls.

Voight is attacked and abducted while trying to help Olive; Roman and Burgess search for a girl who has taken off with a police badge.

Ruzek and Atwater go under cover as prison inmates in order to find the man they believe killed a 10-year-old girl; Burgess and Roman give a tour of the district to some boys they believe are part of the Police Explorers program.

Detectives from New York's SVU come to Chicago to help take down a pedophilia ring; Platt shows her respect for the police.

When Asher is killed while Antonio is on his security duty, Voight and Olinsky make sure he is covered; Halstead and Lindsay go under cover; Kot wants an answer from Lindsay.

Following a big heroin bust, Olinsky learns that the suspects are holding his wife hostage; Burgess and Roman get an assignment that pairs them with a K-9 officer: Roman's former partner (Spencer Grammer).

The intelligence team works to find those responsible for Burgess' wounds; a search of the house provides valuable information.

Lindsay calls on Voight and his unit for help with her first case on the federal task force; Burgess is relegated to desk duty.

Ruzek's father (Jack Coleman) is first on the scene of a double murder; Lindsay prepares for an undercover investigation in Bolivia; Roman and Burgess try to move forward.

Antonio and his sister talk to Elliot Gish about the person they think is responsible for the fire that killed Shay; Lindsay has second thoughts about the task force; Platt's new, sunny demeanor results in curiosity.

Bunny comes to Lindsay with a concern that leads the team to a case that robbery-homicide has been investigating; Voight is suspicious of Bunny's motives.

When Asher is killed while Antonio is on his security duty, Voight and Olinsky make sure he is covered; Halstead and Lindsay go under cover; Kot wants an answer from Lindsay.

Following a big heroin bust, Olinsky learns that the suspects are holding his wife hostage; Burgess and Roman get an assignment that pairs them with a K-9 officer: Roman's former partner (Spencer Grammer).

The intelligence team works to find those responsible for Burgess' wounds; a search of the house provides valuable information.

Lindsay calls on Voight and his unit for help with her first case on the federal task force; Burgess is relegated to desk duty.

Ruzek's father (Jack Coleman) is first on the scene of a double murder; Lindsay prepares for an undercover investigation in Bolivia; Roman and Burgess try to move forward.

Antonio and his sister talk to Elliot Gish about the person they think is responsible for the fire that killed Shay; Lindsay has second thoughts about the task force; Platt's new, sunny demeanor results in curiosity.

Bunny comes to Lindsay with a concern that leads the team to a case that robbery-homicide has been investigating; Voight is suspicious of Bunny's motives.

Emergency response providers put their lives at risk to save others.

A night at an amusement park takes a deadly turn when a roller coaster malfunction leaves lives hanging in the balance; Abby reaches out to Buck; Athena and Hen respond to an unusual home invasion.

Bobby and his team respond to an emergency at a children's birthday party; the crew jumps into action after one of their own is involved in a devastating accident; Athena tries to cope with a tragedy that hits way too close to home.

When Asher is killed while Antonio is on his security duty, Voight and Olinsky make sure he is covered; Halstead and Lindsay go under cover; Kot wants an answer from Lindsay.

Following a big heroin bust, Olinsky learns that the suspects are holding his wife hostage; Burgess and Roman get an assignment that pairs them with a K-9 officer: Roman's former partner (Spencer Grammer).

The intelligence team works to find those responsible for Burgess' wounds; a search of the house provides valuable information.

Lindsay calls on Voight and his unit for help with her first case on the federal task force; Burgess is relegated to desk duty.

Ruzek's father (Jack Coleman) is first on the scene of a double murder; Lindsay prepares for an undercover investigation in Bolivia; Roman and Burgess try to move forward.

Antonio and his sister talk to Elliot Gish about the person they think is responsible for the fire that killed Shay; Lindsay has second thoughts about the task force; Platt's new, sunny demeanor results in curiosity.

Bunny comes to Lindsay with a concern that leads the team to a case that robbery-homicide has been investigating; Voight is suspicious of Bunny's motives.

Burgess and Roman become trapped after Burgess pursues suspicious activity at a convenience store without calling in for backup; the intelligence team receives taser certification.

When an undercover narcotics officer goes missing, Antonio is asked to help find him; Burgess and Roman ask Mouch (Christian Stolte) for help with a squatter situation.

The members of intelligence go under cover at a World Trade conference to assess political threats; Halstead's brother immediately stirs up trouble when he shows up in town.

An investigation into a drug robbery gone wrong reveals Voight has ties to a teen linked to a double murder; Desk Sgt. Platt cares for a young girl.

A case involving one of Chicago's most wanted fugitives hits close to home with Olinsky; an altercation with another officer lands Sean Roman in hot water; Platt helps Nadia prepare for her polygraph test.

After arriving in Chicago to assist Voight and the team with a rape/murder case that has distinct similarities to a decade-old case from New York, Sgt. Benson asks Fin and Amaro to help; the prime suspect asks for a meeting with Lindsay.

Still struggling with a loss, the team must put feelings aside when a cafe is bombed; Atwater winds up in hot water after making a mistake.

Burgess and Roman become trapped after Burgess pursues suspicious activity at a convenience store without calling in for backup; the intelligence team receives taser certification.

When an undercover narcotics officer goes missing, Antonio is asked to help find him; Burgess and Roman ask Mouch (Christian Stolte) for help with a squatter situation.

The members of intelligence go under cover at a World Trade conference to assess political threats; Halstead's brother immediately stirs up trouble when he shows up in town.

An investigation into a drug robbery gone wrong reveals Voight has ties to a teen linked to a double murder; Desk Sgt. Platt cares for a young girl.

A case involving one of Chicago's most wanted fugitives hits close to home with Olinsky; an altercation with another officer lands Sean Roman in hot water; Platt helps Nadia prepare for her polygraph test.

After arriving in Chicago to assist Voight and the team with a rape/murder case that has distinct similarities to a decade-old case from New York, Sgt. Benson asks Fin and Amaro to help; the prime suspect asks for a meeting with Lindsay.

Still struggling with a loss, the team must put feelings aside when a cafe is bombed; Atwater winds up in hot water after making a mistake.

Emergency response providers put their lives at risk to save others.

A night at an amusement park takes a deadly turn when a roller coaster malfunction leaves lives hanging in the balance; Abby reaches out to Buck; Athena and Hen respond to an unusual home invasion.

Bobby and his team respond to an emergency at a children's birthday party; the crew jumps into action after one of their own is involved in a devastating accident; Athena tries to cope with a tragedy that hits way too close to home.

Burgess and Roman become trapped after Burgess pursues suspicious activity at a convenience store without calling in for backup; the intelligence team receives taser certification.

When an undercover narcotics officer goes missing, Antonio is asked to help find him; Burgess and Roman ask Mouch (Christian Stolte) for help with a squatter situation.

The members of intelligence go under cover at a World Trade conference to assess political threats; Halstead's brother immediately stirs up trouble when he shows up in town.

An investigation into a drug robbery gone wrong reveals Voight has ties to a teen linked to a double murder; Desk Sgt. Platt cares for a young girl.

A case involving one of Chicago's most wanted fugitives hits close to home with Olinsky; an altercation with another officer lands Sean Roman in hot water; Platt helps Nadia prepare for her polygraph test.

After arriving in Chicago to assist Voight and the team with a rape/murder case that has distinct similarities to a decade-old case from New York, Sgt. Benson asks Fin and Amaro to help; the prime suspect asks for a meeting with Lindsay.

Still struggling with a loss, the team must put feelings aside when a cafe is bombed; Atwater winds up in hot water after making a mistake.

A mass shooting takes place in an athletic club; Atwater deals with his new assignment; Halstead and Platt try to check up on Lindsay.

Voight and the team help retired Cmdr. Perry extract his nephew from a corrupt unit; Lindsay struggles to stay clean; a woman from Olinsky's past contacts him.

Intelligence pursues heroin kingpin Derek Keyes; Lindsay's downward spiral continues; Olinsky tells Platt about a secret from his past; Roman talks to Burgess about his concerns regarding Ruzek.

Roman and Burgess discover the corpse of a young boy who was reported missing; Burgess talks to Ruzek about Roman's suspicious behavior; Bunny plans to make a statement that could impact Voight's career.

A desperate man searching for his daughter holds a member of the team hostage; Voight learns about the accusations Bunny made regarding a case from his past; Antonio finds out that Olinsky has been keeping a secret.

Voight believes the man who tried to kill him is someone he and Olinsky once put away; Atwater unintentionally spills information about Ruzek's history that disturbs Burgess.

Ruzek's future with the unit is in question after a botched undercover job; a corpse is discovered in an SUV; Lindsay and Halstead move forward with their relationship.

A mass shooting takes place in an athletic club; Atwater deals with his new assignment; Halstead and Platt try to check up on Lindsay.

Voight and the team help retired Cmdr. Perry extract his nephew from a corrupt unit; Lindsay struggles to stay clean; a woman from Olinsky's past contacts him.

Intelligence pursues heroin kingpin Derek Keyes; Lindsay's downward spiral continues; Olinsky tells Platt about a secret from his past; Roman talks to Burgess about his concerns regarding Ruzek.

Roman and Burgess discover the corpse of a young boy who was reported missing; Burgess talks to Ruzek about Roman's suspicious behavior; Bunny plans to make a statement that could impact Voight's career.

A desperate man searching for his daughter holds a member of the team hostage; Voight learns about the accusations Bunny made regarding a case from his past; Antonio finds out that Olinsky has been keeping a secret.

Voight believes the man who tried to kill him is someone he and Olinsky once put away; Atwater unintentionally spills information about Ruzek's history that disturbs Burgess.

Ruzek's future with the unit is in question after a botched undercover job; a corpse is discovered in an SUV; Lindsay and Halstead move forward with their relationship.

Bobby and the team race to help the survivors of a deadly plane crash; Athena deals with chaos at the airport; Bobby confronts his past demons; Athena is out for revenge against teen bullies; Abby delivers an important message from a 9-1-1 caller.

The crew races to an emergency at an Indian wedding; Abby enlists Buck to help her find her mother; Abby meets Athena for the first time; Bobby confronts his past; Hen struggles to make the right decision.

On Valentine's Day, a surprise marriage proposal goes awry with dangerous consequences; Athena attempts to help a desperate woman; Bobby and Chimney pull holiday duty; Abby and Buck go on their first official date.

A mass shooting takes place in an athletic club; Atwater deals with his new assignment; Halstead and Platt try to check up on Lindsay.

Voight and the team help retired Cmdr. Perry extract his nephew from a corrupt unit; Lindsay struggles to stay clean; a woman from Olinsky's past contacts him.

Intelligence pursues heroin kingpin Derek Keyes; Lindsay's downward spiral continues; Olinsky tells Platt about a secret from his past; Roman talks to Burgess about his concerns regarding Ruzek.

Roman and Burgess discover the corpse of a young boy who was reported missing; Burgess talks to Ruzek about Roman's suspicious behavior; Bunny plans to make a statement that could impact Voight's career.

A desperate man searching for his daughter holds a member of the team hostage; Voight learns about the accusations Bunny made regarding a case from his past; Antonio finds out that Olinsky has been keeping a secret.

Voight believes the man who tried to kill him is someone he and Olinsky once put away; Atwater unintentionally spills information about Ruzek's history that disturbs Burgess.

Ruzek's future with the unit is in question after a botched undercover job; a corpse is discovered in an SUV; Lindsay and Halstead move forward with their relationship.

Ruzek's future with the unit is in question after a botched undercover job; a corpse is discovered in an SUV; Lindsay and Halstead move forward with their relationship.

Intelligence searches for a missing teen who they believe poses a threat to students at his school; Atwater wants to make a good impression on a police captain.

When Intelligence follows up on a tip about an upcoming drug trade, the team discovers a man's mutilated body; Burgess helps plan a surprise for Platt.

A decapitated corpse found in Lake Michigan is connected to Voight's social circle; Roman makes a grave error; Antonio makes a decision that could impact Michelle's future -- without consulting Olinsky.

A doctor connected to Voight is investigated after four patients with chemo overdoses are sent to Chicago Med; Platt and Burgess work to clear Roman's name.

A teenage girl is violated during a home invasion; Voight helps a former acquaintance; Platt and Mouch receive upsetting news regarding their upcoming wedding.

Voight wants to make his former cellmate a confidential informant as the unit tries to take down a big cocaine supplier and local dealers; Burgess makes a decision about her relationship with Ruzek; Roman works with Firehouse 51 to fund a wedding.

Ruzek's future with the unit is in question after a botched undercover job; a corpse is discovered in an SUV; Lindsay and Halstead move forward with their relationship.

Intelligence searches for a missing teen who they believe poses a threat to students at his school; Atwater wants to make a good impression on a police captain.

When Intelligence follows up on a tip about an upcoming drug trade, the team discovers a man's mutilated body; Burgess helps plan a surprise for Platt.

A decapitated corpse found in Lake Michigan is connected to Voight's social circle; Roman makes a grave error; Antonio makes a decision that could impact Michelle's future -- without consulting Olinsky.

A doctor connected to Voight is investigated after four patients with chemo overdoses are sent to Chicago Med; Platt and Burgess work to clear Roman's name.

A teenage girl is violated during a home invasion; Voight helps a former acquaintance; Platt and Mouch receive upsetting news regarding their upcoming wedding.