It’s been a tumultuous past few years for every drama in the One Chicago franchise. Cast turnovers have been consistent among all three shows, and many actors have left to try their hands at other things, such as directing and producing, or simply indulging in other projects.

But for every ending, there’s a new beginning, and for every new beginning, there’s a whole bunch of new characters in the spotlight. Whether it’s “Chicago Fire” bringing in a fresh chief, “Chicago P.D.” looking to add a new detective, or two new doctors coming to “Chicago Med,” there are going to be a lot of friendly faces to learn a little more about. But the shows will also wave goodbye to a beloved officer, a dedicated fireperson, and an impassioned doctor. Here’s a list of all of the actors who will be coming to the One Chicago universe … and who will be departing this year.

Doctor Crockett Marcel is set to leave the building. Dominic Rains of “Agents of SHIELD” announced he’ll be departing the drama during Season 10, courtesy of an official announcement posted by Deadline. There’s no word as to whether or not Rains will appear to wrap Marcel’s storyline. It’s possible the character will gracefully fade to black like several others. There was plenty of foreshadowing for that during the Season 12 finale.

During the episode, Sharon Goodwin (S. Epatha Merkerson) compassionately approaches Crockett and tells him that he can take as much time off as he wishes in the wake of a major medical tragedy. Crockett puts off a child’s liver transplant due to a developing infection in the donor — the kid’s father. The father begs Crockett to go ahead anyway, but Crockett’s abundance of caution results in the child dying and his father dying by suicide soon after. Apparently, the incident will make Crockett consider leaving his position at Chicago Gaffney Medical Center. Time will tell where he goes and what he’ll do.

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Entering the “Med” jungle will be two new faces during Season 10. Sarah Ramos will play Dr. Caitlin Lenox, who plans to whip the team into shape after joining as an ED attending. Darren Barnet will play an unnamed pediatric resident with a mysterious background.

Ramos is best known for her time as Haddie Braverman on NBC’s adaptation of “Parenthood.” She also played Jessica on “The Bear,” was Cheryl Pistono on “Winning Time: The Rise of the Lakers Dynasty,” and was younger sister Patty Pryor on “American Dreams.” Barnet has a lot of supporting roles under his belt; he has popped up in the “Road House” remake, “Anyone But You,” “Gran Turismo,” “Love Hard” and “Glass.” Television-wise, he was a regular on “Never Have I Ever” as Paxton Hall-Yoshida. He’s also a voice over artist, playing Kenji Kon on “Jurassic World: Chaos Theory,” Mike on “Skull Island,” and the titular role on “Samurai Rabbit: The Usagi Chronicles.” 

On top of all of this, the show will have a brand-new showrunner in the form of Allen MacDonald. Time will tell how everyone ends up working out.

As fans of “Chicago Fire” know, Captain Wallace Boden (Eamonn Walker) decides to change his entire life during the Season 12 finale, “Never Say Goodbye.” The change was made to accommodate Walker, who has chosen to leave the series as a regular but apparently plans to make recurring appearances. The episode sees Boden battle for the job of deputy commissioner, a role he ultimately wins. That means bidding farewell to his position as chief, and he ends up telling the crew how much he values them on his way out the door. 

Boden’s warm goodbye means that Walker won’t be around much, but he will presumably appear at some point during Season 13. It remains to be seen if he will have a long story arc or simply return for important events. Either way, it’s reassuring to know that he’ll be a comforting figure for Engine 51 in the years to come.

While Boden encourages Chris Herrmann (David Eigenberg) to apply for his vacant position, it looks like he won’t be getting it, as “Chicago Fire” has instead cast Dermot Mulroney as the new chief. Mulroney will be playing Dom Pascal, a gregarious Florida transplant whose sunniness and style will be the opposite of Boden’s. He apparently can buckle down in the heat of the moment, and has a troubled marriage which may soon be behind him. Mulroney is a journeyman actor who has been in everything from “My Best Friend’s Wedding” to “Young Guns” to “August: Osage County.” 

Also set to appear on Season 13 is KaDee Strickland, who will be portraying Monica, Dom’s aforementioned wife. Strickland also has a wide variety of projects under her belt, including roles in “The Grudge,” and “Fever Pitch.” She is perhaps best known to “Chicago Fire” fans as Charlotte King from ABC’s “Private Practice.”

On top of that, Jake Lockett and Jocelyn Hudon will be series regulars for Season 13, and since their characters Sam Carver and Lyla Novak are rapidly becoming important parts of the force, this makes a lot of sense.

Anyone who saw the Season 11 finale of “Chicago P.D.” knows that Hailey Upton (Tracy Spiridakos) has finally severed her ties with Chicago and has left to try out some other branches of law enforcement on for size. The decision arrives after she offers herself up as bait to Frank Matson (Dennis Flanagan), a serial killer who’s got Hank Voight (Jason Beghe) tied up in his basement. After the mission, with Hank safe and sound, Hailey realizes suddenly that her choice to sign up with the force has been driven by her issues with her mother. She feels as if they’re finally resolved and decides to move boldly forward with her life.

Hailey’s exit is spurred by Spiridakos’ desire to do other things acting-wise. However, she hasn’t said no to the notion of a return appearance someday. “I love this group of people, everybody from cast and crew, producers, everybody. This was a really hard decision to make. I’ve been on the show for seven and a half years. So I was just curious about what else was out there and just wanted to switch it up and that was kind of it but it was hard. It was very bittersweet and emotional,” she told Deadline. Time will tell if she’ll ever come back.

The sole new cast member announced so far for “Chicago P.D.” Season 12 is “New Amsterdam” alum Toya Turner. Turner will be playing Kiana Cook, originally named in casting as Yara Page. The character is described as a thrill-seeker who’s tough as nails and doesn’t mind going toe-to-toe with bad guys. The likelihood that she’ll find some action on the mean streets of Chicago is — as anyone who knows anything about “Chicago P.D.” will attest to — quite high.

Turner is perhaps best known for her work on “Warrior Nun,” where she played Shotgun Mary. Her other roles include guest spots on “Grey’s Anatomy,” “The Mick,” “Easy,” and “Empire.” She’s also had a fair amount of stage work under her belt, including a role in “A Raisin in the Sun.”

Time will tell if Bojana Novakovic’s Jo Petrovic will be bumped up to regular status after anchoring a compelling Season 11 storyline. Otherwise, will audiences take to these new faces? Find out when all three One Chicago dramas debut their latest seasons on September 25.