Having begun in October 2012 with Chicago Fire, the Chicago franchise is now close to 9 years old. Given the strong ratings of each of the shows, there are no signs of things stopping anytime soon. Also known as "One Chicago," the franchise has done an excellent job of portraying fictional but realistic events revolving around Chicago's public events.
Only one show in the franchise (Chicago Justice) failed to become popular, leading to its cancellation after only one season. As of May 21, 2020, when all the shows completed their latest seasons, there have been a total of 491 episodes in the franchise. Most of the episodes have been great but a few crossovers really stood out.
The Beating Heart (Chicago Fire) - 8.6
The first part of a three-part crossover rolls in characters from three different shows with ease. The drama starts when Firehouse 51 member Hermann gets stabbed by a troubled kid in a bar and has to be rushed to hospital. Chicago Med thus comes into play. Firefighters and doctors mingle even further when the Firehouse 51 team gets called to put out a fire at a cancer patient's home.
The Chicago Med team learns that this specific patient and several others were diagnosed with cancer but never heard it. The team from Chicago P.D., led by Hank Voight quickly step in to investigate. There's an even better twist when it's revealed that the doctor who diagnosed the patients also treated Voight's wife.
Good Men (Chicago P.D.) - 8.6
The episode continues where the first part of the crossover episode titled "What I Saw" left off. It's all about good men gone bad. When a string of robberies happens at several apartment complexes. The quick-thinking Voight suspects a member of another firehouse who happened to put out a fire at the same complexes a while ago.
To nab the culprit, 21st District detectives ask Squad 3 firefighter Joe Cruz to go undercover at the other firehouse. He achieves his objective but the case isn't closed yet because is a large crew involved. This gives the police a harder job than they anticipated.
Burden Of Truth (Chicago P.D) - 8.6
This is also the second part of a crossover event that happened in February 2020. Though it sticks to common kidnapping and murder themes, it still manages to be entertaining. In it, detectives are on the trail of a drug dealer whose product caused the death of multiple customers.
Previously, Ambulance 61 had responded to a call involving multiple people collapsing after taking opioids. Officer Sean Roman's sister, who had just gone missing, also happened to be friends with one of the victims.
Don't Bury This Case (Chicago P.D.) - 8.6
Sometimes those on the good side of the law find themselves under investigation and this is what happens in this crossover episode. Rescue Squad 3's Kelly Severide aka "Ladies Man" gets investigated for a hit-and-run that turns into a homicide when the victim succumbs to her injuries.
Though Voight suspects that Severide, the evidence against him builds up, leading to some tensions between Firehouse 51 firefighters and 21st District detectives. It turns out that Vought was right. Cox confesses that Ryan was the person behind the accident, not Severide.
Hiding Not Seeking (Chicago Fire) - 8.7
Events in the episode pick up where the 100th episode of Chicago P.D. left off. The stakes are high because there is another bomb involved. When Trudy gets to a local TV station for an interview, an explosion happens. Voight learns that the suspect wants to destroy the media because of a damaging story.
Chief Voight thus meets with Chief Boden and convinces him to let Dawson and Brett go undercover in order to track down the suspect. Though he is skeptical about it, the mission proves to be a success.
Infection: Part I (Chicago Fire) - 9.0
This is definitely an appropriate episode to watch during the current Covid climate as it involves a deadly disease. And it sure is quite the thriller. In it, hell breaks loose when Matthew Casey notices a guy collapsing during a Chicago Bears game. Upon closer inspection, it's revealed that the man has a flesh-eating infection on his leg. He also keeps repeating the abbreviation "BRT."
More victims succumb to the infection and while responding to a fire at Central Chicago University (CCU), the Firehouse 51 team also notice "BRT" initials on the walls. Investigations point to a lab assistant who had been threatening people with an apocalyptic-type disaster.
Going To War (Chicago Fire) - 9.1
The Firehouse 51 team has had to deal with some complex scenarios and this episode presents one of them. A raging blaze consumes a 25-story apartment. Things get even more complicated when it's revealed that Detective Jay Halstead’s father is trapped inside. Sadly, he dies, setting a somber mood that stays throughout the crossover event.
That's not the only heartbreaking moment. Otis witnesses a mother and baby die in an elevator too. As a result, he develops PTSD and visits Dr. Charles for therapy sessions. Kidd then risks her life to rescue Severide. Jay Halstead also has an action hero. Despite Voight thinking he isn't stable to work, he goes full action-hero, hunting the suspect and killing him.
Deathtrap (Chicago Fire) - 9.1
There have been a couple of times when the job has been too big for Station 51 alone. In this episode, several Chicago firehouses are called when a fire breaks out as teens are holding a party inside an industrial warehouse. In an unexpected development, Detective Olinsky's daughter is said to be one of the victims.
Watching Olinsky plead with the firefighting teams to save his daughter as the chief makes the call to pull his men out is indeed heartbreaking. What's worse is the discovery that the fire was set intentionally set. Things get even more complicated when the owner, who has been singled out for investigation, kills himself.
A Dark Day (Chicago Fire) - 9.1
This is the first-ever crossover event in the franchise. And it sure does lay a good foundation. In it, a bomb goes off during a "Race Against Cancer" event outside Chicago Medical Center. Gabby is trapped, so the people from Firehouse 51 work hard to rescue not only her but also the doctors that work at Chicago Medical.
Chief Hank Voight and his team investigate the matter and learn that it's a revenge act against Chicago's finest officers. Voight soon goes after a group of diplomats from Syria who came to town for their ambassador's backdoor liver transplant.
I Am The Apocalypse (Chicago Fire) - 9.1
One of the best ever crossover episodes combines explosions and viruses to good effect.. Events kick off with the Firehouse 51 team rescuing and transporting victims of an industrial chemical leak to Chicago Memorial. At the hospital, a patient carrying a grenade claims to be in possession of a deadly airborne disease.
When a member of Firehouse 51 tries to stop him, he gets injured in the explosion. The hospital is quickly put on lockdown to determine how severe the airborne virus is.