As such, we’ve assembled this handy guide to help you get your bearings, and

to help set your mind at ease about the future of some of the essential members

of the firehouse. Sylvie Brett (Kara Killmer) was confirmed to be leaving before

season 12 even started. She confirmed that she accepted the marriage proposal from Matt Casey (Jesse Spencer) and plans to get married a month after the season 12 premiere. The only tricky part is determing how long a month is in series time versus real time. The odds are fairly high that the Brettsey wedding will serve as the mid-season finale, especially since we’re getting a much shorter season than usual. There’s been lots of Kelly Severide (Taylor Kinney) speculation over the last eight months, but his return in the season 12 finale proved that he’s still very much the driving force of the show.

Andrea Newman, Fire’s showrunner, recently told that Hello! Magazine that the character remains a “critical part” of the show’s structure and its baseline appeal, so the smart money is on Severide sticking around for the duration of the season (and hopefully beyond). Blake Gallo (Alberto Rosende) was the first to go in season 12. He only had one scene, and it was, fittingly, his goodbye to the rest of the 51 team. The character’s exit was a bit abrupt, but it was still led to some very heartfelt moments, and helped prepare the fans for all of the change that’s going to come. Plus, promo photos had us worried that Gallo was going to get killed off, so we’re frankly thrilled that he’s relocating to Michigan to live with his extended family.

That means he could come back at some point! Derrick Gibson (Rome Flynn) is the wild card of season 12. He’s set to debut in episode 2, and he will effectively serve as the replacement for Gallo. Andrea Newman has described Gibson as a person who likes to play things close to the chest, so it’ll be interesting to see how he clashes with the more open– and dramatic– members of the firehouse. Gibson’s longevity on Chicago Fire will obviously depend on his popularity with fans and the desire of his actor to stay on, but it’ll be exciting to get a brand new centerpiece for the 51. The promo for episode 2 really made it seem as though Joe Cruz (Joe Minoso) was going to leave the 51 for good. He says, verbatim, “I think it’s time for me to leave 51.”

It’s a great hook for an episode, and it will lead to some memorably tense scenes between him and Severide, but we seriously doubt that Cruz will walk. The character is a fan favorite, and given all of the changes that the show has gone through, they wouldn’t write off a character just for the sake of shocking fans. We’re confident that Severide and Cruz will be able to squash their beef and continue to put out fires together for the rest of the season.