Adrian S Burrows Sr/NBC

Season 12 of “Chicago Fire” may be a shortened season, but it’s going to be an emotional rollercoaster, according to executive producer Andrea Newman. In a new interview with Variety, Newman — who became the sole showrunner this season after previously serving as co-showrunner with Derek Haas — teased that the new season “really jumps out with a bang, literally.”

With both Alberto Rosende and Kara Killmer, who portray Blake Gallo and Sylvie Brett, respectively, exiting the series this year, and the return of Taylor Kinney’s Kelly Severide, nothing is off limits.

In the Season 11 finale, Casey (Jesse Spencer) proposed to Sylvie — who is wearing a ring in the below photo, for what it’s worth — Kidd (Miranda Rae Mayo) left town to go find her husband and Mouch (Christian Stolte) was left bleeding out in the hospital after being hit by shrapnel during a call. Season 12, premiering on Jan. 17 at 9 p.m. ET, will pick up six months after the last episode.

Read Variety‘s full Q&A with Newman below.

Heading into the premiere, we have a character leaving and an update on Mouch. On a scale of 0 to Leslie Shay’s death, how emotionally prepared should audiences be?

I would prepare for level 10 out of 10. There’s a lot going on and it really jumps out with a bang, literally. It’s quite a rollercoaster ride. All of these actors who have been waiting to jump back in and just bring it with everything they have, they’ve been at the top of their game. It’s a great episode and lots of emotion.

Was the vibe different on set this time around, coming back post-strike after such a long break?

It was. I think buzzy is the world I’d use! Plus, having Taylor back was a thrill for everybody, and he was as jazzed as can be. The energy levels were through the roof.

This is also your first time solo showrunning and it’s an abbreviated season, so how has that been?

Well, Derek is very missed, as a person and a presence and voice. He created the show, but I really am incredibly lucky as we have such a great team here. It really is a team effort. We really use 51 as our inspiration — how tight they are, they hang together and always have each other’s back. I feel like we have a really amazing staff and production. Our producers are incredible and our cast is incredible. It’s always felt very familyish, so it never feels like I’m doing it solo.

Well, let’s talk about Taylor’s return after his leave of absence. Is he back full-time?

He’s back, is what I’ll say. It’s a shortened season, but he’s back and Severide’s centerstage in this season.

Miranda Rae Mayo as Stella Kidd, Kara Killmer as Sylvie Brett and Hanako Greensmith as Violet Mikami in the season premiereAdrian S Burrows Sr/NBC

OK. Last we saw, Kidd left to go get him from his out-of-town job and bring him home. What’s the vibe of their relationship now?

There’s a whole new dynamic between them. The heat and the sexual tension are as high as ever. They can’t keep their hands off each other, as usual, and yet, there’s this new dynamic that is present between them, something we haven’t seen before. I think Violet had a line that was something like, “It’s like watching two big cats circling each other, you’re not sure what’s going to happen next.” There’s an edge in the air between them but the main case OFI case, which is the big case that Severide’s been dealing with, is going to bring up a lot of tension between them and explore what’s been happening these last six months and what they’ve been going through.

Alberto announced he is leaving this season and we know this episode is his last. What has the process been like, since he told you he was leaving and then having to write him off?

We love Alberto so much. We love that character so much, and he had such a strong season last season. There was something that almost felt like the Super Bowl about it, like the quarterback who retires after a Super Bowl — not that he’s retiring from the business, but his leaving makes some sense because he had such a strong season and as a character, has evolved so much. We definitely lean into that and Gallo has very specific reasons for leaving when he does. It’ll affect everybody and from a writing standpoint, it’s sad not to have Gallo to write for, but like I said, it felt natural in some strange way. He will be very missed by all.

If he hadn’t left, was the plan to make Gallo and Violet (Hanako Greensmith) endgame?

I think they’ve become such good friends that that would have been a twisty-turny place to get to. I think their relationship really evolved into a beautiful friendship. So in terms of Violet, I don’t feel like that was going to be endgame. Their friendship became so important at that stage.

Daniel Kyri as Darren Ritter, Alberto Rosende as Blake Gallo and David Eigenberg as Christopher HerrmannAdrian S Burrows Sr/NBC

Alright, let’s talk about Casey and Brett. He proposed at the end of the last season. Will we see her decision early on in the premiere?

We will find out pretty quickly what Brett’s plans are, but her plans — made with the best of intentions — don’t go as she wants them to. So we’ll find out a lot quickly and then things will change; there will be a rollercoaster.

So, will Jesse be back this season?

Jesse Spencer will be back — our beloved Matt Casey. We can’t live without him. He’s truly the best.

Well, we know Kara is leaving this season as well. In how many episodes will we see her?

I’ll say that we have a shortened season and she’s in a chunk of this season. She’s got a journey of her own to take before we let her go.

What can you say about Rome Flynn joining as Jake Gibson?

He’s phenomenal. He’s an electric presence and a very different energy than a lot of our guys at 51. He’ll be shaking things up. As a character, there are a lot of layers to peel back on Gibson. He’ll be a fun new element to rock 51 a little bit.

This interview has been edited and condensed.