Summary

• Crossovers in the One Chicago universe create rich stories across multiple shows and encourage audience engagement.
• Chicago Fire, P.D., Med, and Justice all intersect in the Dick Wolf universe, with intricate plotlines and character developments.
• Intense crossovers with Law & Order: SVU tackle heavy subjects like assault, drug use, and corruption, showcasing strong female characters.

The One Chicago universe has grown well beyond the original Law & Order universe that it spin off from, and its crossover episodes have created rich stories across the franchise. Crossovers between shows in the same universe can be exciting events that follow one plot across multiple episodes and nights. They're also an effective way to encourage audience to watch all the shows across the franchise so that they're up-to-date with the arcs on each show.

Several series encom the One Chicago franchise, including Chicago Fire, Chicago P.D., Chicago Med, and Chicago Justice. The shows have also been known to crossover with Law & Order: SVU, another popular and long-running series in the Dick Wolf universe. Dick Wolf created the Law & Order franchise and is known as one of the most successful television producers based on the longevity of the shows and how far-reaching they have become. Law & Order, the original series, gained popularity for its innovative take on the criminal justice system, and the universe has only expanded from there.

14 Some Make It, Some Don't / Don't Bury This Case

Chicago Fire: Season 5, Episode 9; Chicago P.D.: Season 4, Episode 9

Although Chicago Fire came before Chicago P.D., both shows were equally successful, and their crossovers were a big deal. In the two-part events "Some Make It, Some Don't" and "Don't Bury This Case," Lt. Severide (Taylor Kinney) faces huge problems after he is framed for causing a hit-and-run car accident. This causes intense friction between the Firehouse 51 and Intelligence teams, as neither one wants to step on the other's toes.

While everything works out in the end, the crossover is a reminder that while the firefighters and officers are on the same team, their interests may not always align. This was also very different from other One Chicago crossover events. Normally, the three teams (firefighters, investigators, and medical teams) work together to save lives and protect the city. In this crossover, they were set up against each other, and this had little to do with anything but discovering the truth about Severide.

13 Off The Grid / Burden of Truth

Chicago Fire: Season 8, Episode 15; Chicago P.D.: Season 7, Episode 15

The issue of the opioid crisis and teen drug use is tackled in this Fire and P.D. crossover. As the investigation progresses, the drug dealers are connected to a homicide, and both teams have their hands full. One of the more exciting parts of the cevent is that Sean Roman (Brian Geraghty) returns to wrap up his character arc and make a final appearance while looking for his sister in Chicago. This allowed several people who knew him to show up and help in the crossover.

In the end, Roman's sister is killed, tragically ending his story, but seeing him get closure with the other P.D. officers is an important step for the show. The return brought in a lot of viewers because this was Sean's first time in the One Chicago franchise since 2016. It starts when he shows up on Chicago Fire after a recent fire involves some of his sister's friends. The crossover ends with Sean seeking revenge and Voight letting him off the hook in a controversial but happy ending for the character.

12 What I Saw / Good Men

Chicago Fire: Season 7, Episode 15; Chicago P.D.: Season 6, Episode 15

When a firefighter is suspected of being involved in a robbery, Cruz (Joe Minoso) goes undercover to discover who is responsible. He brings his findings to Voight (Jason Beghe) and the Intelligence team, but tensions soon arise when Voight must balance keeping the firefighters happy while doing everything he can to bring the thieves to justice.

The episodes do an excellent job showing the nuance of working in a protective job for the city and how easily that power can lead to corruption or empathy depending on who is involved. This really shows the divide between the departments, with a strong separation of law enforcement principles and political aspirations, as the mayor doesn't want either department to come out of this looking bad. Voight won't give up, though, and it is clear he will get his way in the end.

11 Comic Perversion / Conventions

Law & Order: SVU: Season 15, Episode 15; Chicago P.D.: Season 1, Episode 6

One of the earliest crossovers for Chicago P.D., Detective Lindsay (Sophia Bush), appears at the end of the episode "Comic Perversion" to inquire about cases of sexual assault in Chicago. After SVU's Detective Olivia Benson (Mariska Hargitay) successfully convicts the perpetrator in her case, she s the team in Chicago to track down a serial killer with an M.O. of assault. This crossover deals with the heavy subjects of rape culture and how easily abs can walk away unscathed.

Between Lindsay and Benson, the episodes are chock-full of strong female characters who fight for the rights of survivors. This was the first crossover that showed the One Chicago series in the same world as Dick Wolf's other successful franchise, Law & Order, and specifically the SVU brand. It was fun to see fan favorites like Amanda Rollins (Kelli Giddish) and Odafin Tutuloa (Ice-T) return as well, and it set up a great future for the One Chicago crossovers.

10 A Dark Day / 8:30 PM

Chicago Fire: Season 2, Episode 20; Chicago P.D.: Season 1, Episode 12

This crossover was especially relevant at the time of its airing because it explored acts of domestic terrorism surrounding public events in the city. There is a bombing at a hospital, and many loved ones of both the firefighter and the officer characters are involved. Not only are the lives of the people injured in the bombing at stake, but also the lives of the people in need of life-saving care who were already itted.

This Chicago Fire episode is considered one of the best in the show's history, and the Chicago P.D. episode is just as good.

As the doctors work to save everyone, and the officers investigate the bombing, the episodes handle the gravity of the situation with care, and show how many pieces of infrastructure are affected by an attack. This Chicago Fire episode is considered one of the best in the show's history, and the Chicago P.D. episode is just as good. Seeing multiple detectives from one show turning up to help the Firehouse 51 was great, and the entire crossover was emotionally draining.

9 Nobody Touches Anything / Chicago Crossover / They'll Have To Go Through Me

Chicago Fire: Season 3, Episode 7; Law & Order: SVU: Season 16, Episode 7; Chicago P.D.: Season 2, Episode 7

In "Nobody Touches Anything", the of Firehouse 51 find a mysterious box of photographs that are all of missing children. It turns out that these children are cataloged in a New York database, leading them to enlist the help of the Special Victims Unit. Before they head to New York, it's revealed that Detective Lindsay's brother is among the missing children, and the case is personal. The conspiracy deepens as the team finds out the photos are connected to a ring of child pornographers who are still victimizing children.

When it becomes clear that the leaders of the ring are on to the investigators and have returned to Chicago, the group goes back as well. Lindsay's brother re critical information and helps the officers eliminate the ring, which brings closure to him and Lindsay. This backstory is an important step in Lindsay's character development and makes the crossover intriguing. The episodes added more facts about Erin Lindsay in Chicago P.D. making her character seem all the more real.

8 Profiles / Hiding Not Seeking

Chicago P.D.: Season 5, Episode 15; Chicago Fire: Season 6, Episode 13

In this two-part event, P.D. looks to the firefighters to help them catch the person responsible for a series of bombings across the city. As Trudy Platt (Amy Morton) is one of the first victims of the bombings (although she survived the incident), the two agencies go into high gear to prevent further attacks. The culprit is quickly identified and brought to justice, but his actions lead to the bigger problem of illegal explosive dealing in the city.

Due to the lead they have on the dealer, Dawson (Monica Raymund) and Brett (Kara Killmer) go undercover in the second part of the crossover, as they try to get more information about the dealings. The best parts of this entire One Chicago crossover involved the interactions between Boden and Voight, as they are two men who are used to running the show but had to focus on working together here. It was also a straightforward case, which was nice after some more tumultuous crossovers.

7 The Beating Heart / Malignant / Now I'm God

Chicago Fire: Season 4, Episode 10; Chicago Med: Season 1, Episode 5; Chicago P.D.: Season 3, Episode 10

This was the first One Chicago crossover to include Chicago Med, which was introduced in a backdoor pilot the year before. The hospital setting was very important here. This three-part crossover is a particularly pivotal episode for Chicago Fire because it sees the fate of Christopher Herrmann (David Eigenberg) hanging in the balance. After Herrmann is stabbed, he is taken to the hospital, where Dr. Rhodes (Colin Donnell) performs surgery on him.

Herrmann ultimately pulls through, but in the process, the officers of Chicago P.D. realize there is a case of corruption in the hospital that may have affected Voight's (Jason Beghe) wife many years ago when she was being treated for cancer. While at the hospital waiting to see if Hermann will make it, the team discovers chemotherapy overdoses at the hospital, and that is when Voight realizes this criminal case is hitting a little too close to home. He sets out to find those responsible for her death.

6 Going To War / When To Let Go / Endings

Chicago Fire: Season 7, Episode 2; Chicago Med: Season 4, Episode 2; Chicago P.D.: Season 6, Episode 2

The firefighters of Firehouse 51 face one of their greatest challenges in "Going To War" when they must rescue an entire apartment building full of people. Soon, the victims of the fire are rushed to the hospital, and Chicago Med is brought into the fold. In the final installation of the crossover on Chicago P.D., it's revealed that the fire was started intentionally to target Jay (Jesse Lee Soffer) and Will Halstead's (Nick Gehlfuss) father, who lived in the building.

It's this personal element that makes the stakes of the event so high and the story so compelling. The fire itself was one of the scariest on Chicago Fire at the time, and when Pat Halstead (Louis Herthum) died, it made the entire crossover feel tragic and sad. It also made it all the more important for the Chicago P.D. team to find out who caused the fire and bring them to justice. With Jay making this personal, it also remains one of the most harrowing One Chicago crossover events.

5 Three Bells / A Little Devil Complex

Chicago Fire: Season 3, Episode 13; Chicago P.D.: Season 2, Episode 13

"Three Bells" / "A Little Devil Complex" continues the story of trying to catch Leslie Shay's (Lauren German) killer after her shocking death, but the heroes of Firehouse 51 hit many roadblocks. Adrian Gish (Robert Knepper) is believed to be responsible, but there is not enough evidence to tie him to the crime. Meanwhile, the officers in P.D. further the investigation of Gish and ultimately bring him to justice.

The mystery and tragedy surrounding Shay's death plagued of the One Chicago universe, and the arc of these episodes provided a satisfying end. Seeing Antonio Dawson (Jon Seda), Kim Burgess (Marina Squerciati), and Sean Roman (Brian Geraghty) come in to help with the arson investigation that led to Shay's death was great, as of both the police and fire departments were adamant about getting justice for their fallen friend.