Contains general spoilers for “Chicago Fire” Season 13

In a few weeks, “Chicago Fire” returns to the airwaves with a fresh season, and the drama’s showrunners have begun to let fans know just what sort of changes to expect in the aftermath of that big Season 12 finale bombshell about Kelly Severide’s (Jesse Spencer) connection to newbie Jack Damon (Michael Bradway). To recap, Damon reveals that they’re half-brothers through their abusive late pop, Benny (Treat Williams), and Kelly’s left in shock.

The fact that Benny resurfaces just as Kelly gets his footing back following his return to the firehouse from his ATF work and just as he and Stella (Miranda Rae Mayo) have begun to contemplate parenthood (which might be a big mistake) hasn’t been lost on showrunner Andrea Newman. “We kept feeling like this is haunted season 13,” she told Entertainment Weekly ahead of the Season 13 premiere. “It’s kind of like people’s past ghosts coming back. That’s very true for Severide, where he’s worked really hard to put his father in the rearview mirror and become his own firefighter. So to suddenly have Benny’s son, his half-brother, appear in his life, it makes him have to re-explore all of that stuff. So it brings up a lot for Severide and that relationship is complicated and juicy and there’s lots of stuff that will play out between the two of them early on.”

It looks like fans can anticipate some “juicy” family drama instead of brotherly love between the Severide siblings. But this isn’t the first time that Kelly’s had to cope with the appearance of a sudden, previously unknown half-sibling.

Longtime fans of “Chicago Fire” will recall that Kelly Severide has another half-sibling. Katie Nolan (Brittany Curran) is another of Benny Severide’s kids, and when Kelly meets her in Season 2, things are initially rocky between them. Katie is a cook who also has her own scars from being raised by Benny, which means she’s initially reluctant to get close to Kelly. Eventually, however, the two siblings find common ground.

More than simply agreeing to get along, Kelly and Katie become quite close. He even attends her culinary school graduation and introduces her around at the firehouse. She and Otis (Yuriy Sardarov) briefly date, but when Vince Keeler (Jake Weary) kidnaps her, she decides it’s best to start fresh in another city. Katie resurfaces when Benny passes away during Season 7, and Kelly takes the opportunity to introduce her to Stella. She and Otis talk about old times together, indicating that they’ve remained friends since she left town. She’s currently working in Colorado as a sous chef and does not return to town for Kelly and Stella’s wedding or Otis’ funeral.

Time will tell if we ever get to see all three Severides in the same place at the same time, but Kelly definitely won’t be a stranger to half-sibling drama when “Chicago Fire” returns on September 25.