A Guide to Every Must-Watch One Chicago Crossover Episode (2024)

The One Chicago universe is a captivating smash, and as Chi-Hards keep coming back for more, One Chicago crossover episodes remain some of the most memorable moments in the franchise's history.

Combining the casts of the flagship Chicago Fire, Chicago Med, and Chicago P.D., One Chicago crossovers weave together the challenges of the city's most dedicated rescuers, creating a pulse-pounding narrative. These episodes not only raise the bar for twists and turns, but deepen the bonds between fan favorites across each show. Firehouse 51 never hesitates to run into danger alongside P.D.'s Intelligence Unit, and they'd never discount the critical role the Chicago Med's nurses and doctors play when the ash finally settles. Every so often, the going gets so tough that 's Olivia Benson (Mariska Hargitay) receives a call from Chicago for backup.

RELATED: Where to Watch and Stream Chicago Med, Chicago Fire, and Chicago P.D.

The One Chicago crossover episodes have become a hallmark of Dick Wolf's sprawling franchise. Here is a guide to every essential One Chicago crossover episode that delivers those high-octane thrills — official episode synopsis included.

Must-See crossover Episodes of Chicago Fire, Chicago Med, andChicago P.D.

Chicago Fire Season 1, Episode 23 ("Let Her Go"): Chicago P.D.'s Backdoor Pilot

Plot: "Lt Casey must work with Voight and the Intelligence Unit, Shay grows increasingly excited about the prospect of motherhood, and everyone comes together to support the opening of Molly's."

Law & Order: SVU Season 15, Episode 15 ("Comic Perversion") | Chicago P.D. Season 1, Episode 6 ("Conventions")

SVU Plot: "A controversial, misogynistic comic makes jokes about sexual assault at one of his shows. When he is accused of rape, Benson is happy to arrest him, but Barba feels the case is weak."

P.D. Plot: "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."

Chicago Fire Season 2, Episode 20 ("A Dark Day") | Chicago P.D. Season 1, Episode 12 ("8:30 PM")

Fire Plot: "Firehouse 51 joins forces with the Chicago Police Department to combat a massive explosion that leaves the city in carnage and one of the crew missing."

P.D. Plot: "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."

RELATED:One Chicago Creator Dick Wolf's Movies and TV Shows

Chicago Fire Season 3, Episode 7 ("Nobody Touches Anything") | Law & Order: SVU Season 16, Episode 7 ("Chicago Crossover") | Chicago P.D. Season 2, Episode 7 ("They'll Have to Go Through Me")

Fire Plot: "Severide returns from Las Vegas with a life-changing secret to share. Plus, the crew makes a disturbing discovery at the fire scene."

SVU Plot: "Sgt Voight and Detectives Lindsay and Halstead work with Sgt Benson and the SVU as they investigate the roots of a child p*rnography site, but tension between Benson and Voight threatens the investigation."

P.D. Plot: "The intelligence unit joins forces with detectives Rollins, Amaro, and Benson to bring down a child p*rnography ring once and for all."

Chicago Fire Season 3, Episode 13 ("Three Bells") | Chicago P.D. Season 2, Episode 13 ("A Little Devil Complex")

Fire Plot: "More clues emerge about the fire that killed Shay, leading Severide to a former nemesis; Shay's sister visits; Cruz is faced with a surprise; Boden tries to help his father."

P.D. Plot: "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."

Chicago Fire Season 3, Episode 19 ("I Am the Apocalypse"): Chicago Med's Backdoor Pilot

Fire Plot: "Members of Firehouse 51 transport victims of a gas leak to nearby Chicago Med; an armed patient claiming to be carrying a deadly airborne disease forces Chicago Med into lockdown."

Chicago Fire Season 3, Episode 21 ("We Called Her Jellybean") | Chicago P.D. Season 2, Episode 20 ("The Number of Rats") | Law & Order: SVU Season 16, Episode 20 ("Daydream Believer")

Fire Plot: "An apartment fire with connections to rape and attempted murder leads to a joint investigation with the CPD and Sgt. Benson of the NYPD's Special Victims Unit; Dawson risks her life during a call."

P.D. Plot: "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."

SVU Plot: "Members of the Chicago PD come to New York to assist the SVU in their pursuit of the prime suspect in a case of rape and murder that resembles a case from a decade ago. A kidnapping raises the stakes."

Chicago Fire Season 4, Episode 10 ("The Beating Heart" | Chicago Med Season 1, Episode 5 ("Malignant")| Chicago P.D. Season 3, Episode 10 ("Now I'm God")

Fire Plot: "A member of Firehouse 51 is treated for life-threatening injuries; Cruz searches for Freddie; Mouch has a surprise for Trudy; Chili's behavior worries Brett and Jimmy."

Med Plot: "Rhodes and Zanetti race to save a member of Firehouse 51, April's brother struggles during his first day at the hospital, and a woman saved from a burning building leads to a bigger mystery."

P.D. Plot: "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."

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Law & Order: SVU Season 17, Episode 14 ("Nationwide Manhunt") | Chicago P.D. Season 3, Episode 14 ("The Song of Gregory William Yates")

SVU Plot: "Detectives from Chicago arrive in New York on the trail of two escaped killers they helped convict. They team up with the SVU to track them down."

P.D. Plot: "After escaping from a New York prison, convicted killer Gregory Yates (Dallas Roberts) heads to Chicago; SVU members Benson and Tutuola help investigate a triple homicide in Chicago; the team seeks a connection between Yates and a missing woman."

Chicago Fire Season 5, Episode 9 ("Some Make It, Some Don't") | Chicago P.D. Season 4, Episode 9 ("Don't Bury This Case")

Fire Plot: "Dawson and Casey face legal issues as they try to retain legal guardianship of Louie; Severide continues to look for a bone marrow procedure to help Anna; Brett opens up to Dawson."

P.D. Plot: "Severide is brought in for questioning after it is discovered that his car has been involved in a deadly crash; Lindsay considers meeting her estranged father."

Chicago P.D. Season 5, Episode 16 ("Profiles") | Chicago Fire Season 6, Episode 13 ("Hiding Not Seeking")

P.D. Plot: "A string of bombings is targeting members of the media; the team enlists Firehouse 51 to help examine the devices and prevent the next attack."

Fire Plot: "Voight requests that Brett and Dawson go undercover, and Chief Boden unwillingly agrees; Zach and Kidd's relationship hits an obstacle; Cruz struggles to express his true feelings for Brett."

Chicago Fire Season 7, Episode 2 ("Going to War") | Chicago Med Season 4, Episode 2 ("When to Let Go") | Chicago P.D. Season 6, Episode 2 ("Endings")

Fire Plot: "Firehouse 51 bands together to fight a raging fire on the 20th floor of the residential high-rise where Jay and Will Halstead's father lives and has gone missing; in the midst of the chaos, Brett learns unsettling information about her new partner."

Med Plot: "Chicago Med, Fire, and P.D. cross paths when a high-rise fire floods Med with victims, including Will and Jay Halstead's father; Rhodes must save the life and career of Stella Kidd; Manning treats a burn victim; Charles assesses a distraught Otis."

P.D. Plot: "Intelligence joins forces with Firehouse 51 after a devastating high-rise fire is ruled arson, and Halstead, who has a tragic connection to the fire, struggles to stay objective as he gets deeper into the investigation."

Chicago Fire Season 7, Episode 15 ("What I Saw") | Chicago P.D. Season 6, Episode 15 ("Good Men")

Fire Plot: "A spate of robberies comes to light after a firehouse lockbox key goes missing; Sgt. Hank Voight suspects a firefighter may be involved, and with Boden's support, he recruits Cruz to go undercover to help sniff out any suspicious activity."

P.D. Plot: "When Cruz's undercover work reveals a lead in a case tracking multiple robberies, the situation escalates quickly, causing friction between Voight's Intelligence Unit and the Chicago Fire Department."

RELATED: You May Have Missed These 3 Crossover Moments During the One Chicago Premieres

Chicago Fire Season 8, Episode 4 ("Infection: Part I") | Chicago Med Season 5, Episode 4 (Infection: Part II") | Chicago P.D. Season 7, Episode 4 ("Infection: Part III")

Fire Plot: "A rare but deadly bacteria takes its toll on numerous victims around the city, leaving Chicago's finest first responders to work together alongside the CDC to resolve the dangerous situation; Severide suspects something bigger is happening."

Med Plot: "Dr. Manning's actions with a recent patient lead to serious repercussions; April and Noah disagree over a patient who is injured after a beating; Dr. Charles is visited by a childhood friend with a surprising revelation."

P.D. Plot: "After zeroing in on a suspect responsible for bioterrorism, the P.D. prepares to undertake its biggest manhunt yet; Upton is torn between helping track down the perp and providing emotional support to a scared young girl who needs her."

Chicago Fire Season 8, Episode 15 ("Off The Grid" | Chicago P.D. Season 7, Episode 15 ("Burden of Truth")

Fire Plot: "A series of teen opioid overdoses sees Severide partner with Sean Roman, but he begins to suspect there's more to the story than his old friend is telling him; Casey tries to be there for Brett as she considers her birth mother's offer to meet."

P.D. Plot: "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."

Watch every episode of Chicago Fire, Chicago Med, and Chicago P.D. on Peaco*ck.