The NBC hit will be back for another season in the fall This story includes spoilers

from the season 12 finale of Chicago Fire. The season 12 finale of Chicago Fire packed

quite a few punches — and that’s not even counting the brawl that went down when

Firehouse 51 arrived on the scene of a restaurant fire. Ahead of the episode, viewers learned that Eamonn Walker, who has played Chief Wallace Boden since the show’s inception in 2012, was stepping down as a series regular, although he is likely to appear here and there on a recurring basis. But how he would leave remained a mystery. After all, he didn’t seem to want to throw his helmet into the ring for the Deputy Commissioner job, right? But when a save at a construction site went awry and the foreman went in critical condition after insisting that his team be saved first, Boden had an epiphany about leadership — and announced he was going after the job only a few days before the new D.C. would be appointed. Shortly after sharing that news with the team, he spoke privately with Christopher Herrmann (David Eigenberg) about his desire for him to step into the Chief role.

“You can look after our family,” Boden told Herrmann, who responded, “I’m nobody.” Of course, we all know he’s not, that he “leads with his heart,” as Boden said. That wasn’t the only change facing the fire fam: Mouch (Christian Stolte) struggled to adjust to the new rig and also revealed he was studying for the lieutenant’s test with the help of his wife, Trudy. In the previously referenced brawl, Sam Carver (Jake Lockett) and Jack Damon (Michael Bradway) wound up in a physical fight with a restaurant owner and father who was mean to his son and refused care for his bad burn, which he may or may not have caused himself. For Carver, this hit close to home, as he was abused and burned by family members as a child, but Lt. Stella Kidd (Miranda Rae Mayo) wasn’t sure why Damon was so triggered.

Soon after, Carver argued with his love interest, Paramedic in Charge Violet Mikami (Hanako Greensmith), who accused him of still having a crush on Kidd. But he insisted that wasn’t the case, that she was holding him at a distance and struggling to accept that they were something more because of the death of her former flame, Chief Hawkins. He also confessed that he was falling in love with her before leaving. Later, Stella told Violet about Carver’s past and shared that he’d taken another furlough. Just before learning that Boden had landed the D.C. job, Kidd and her husband, Kelly Severide (Taylor Kinney) started talking about having children, but little did they know the family bombshell that was still to come…

The team gathered in Boden’s office to congratulate him and see him off. He insisted on not having some grand goodbye, and Kidd stopped him. “That’s the thing,” she said. “There are people you say goodbye to, and people you can never say goodbye to because they’ve become too much a part of who you are. They shaped you, trained you, taught you everything you know even. Darren Ritter (Daniel Kyri) chimed in, “I look around sometimes and feel like I was born here. I didn’t really know what being a firefighter was before, nor a brother.” “Now you get to do that for the whole CFD,” said Severide.

“And they’ll see how lucky we were.” “You made 51 a family, Chief, and this firehouse a home,” said Joe Cruz (Joe Miñoso), and Mouch concluded, “Thank you, Chief, for being the best friend and leader anyone could ask for.” Never miss a story — sign up for PEOPLE’s free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer​​, from celebrity news to compelling human interest stories. As the group disbanded to get back to work, Damon approached Severide to explain why he lost his cool at the restaurant fire — and the real reason he came to 51. “That guy at the restaurant, the father, he was being mean and he was treating that younger kid like dirt, and I had a father like that too,” he said. “His name was Benny Severide.” Whoa. Kelly has a brother he never knew about. Benny was Kelly’s father, played by the late Treat Williams. The character died of a stroke in season 7.