It was a night for goodbyes on “Chicago Fire.” The Season 12 finale was the final episode for Eamonn Walker as Battalion Chief Wallace Boden. The actor, who has served as the chief of Firehouse 51 since the series debuted in 2012, will no longer appear as a series regular beginning next season.

After a hard call, Boden decided to throw his hat into the ring for the job of Deputy Commissioner, mostly because those in the running (specifically Chief Robinson) wouldn’t be able to lead in a way that the department deserves. If he was to become DC, he’d have to leave 51 for good. After telling the team, he then told Herrmann (David Eigenberg) that in the slim chance he got the promotion, he’d like him to take over his job.

Ultimately, Boden thought he was getting passed over. However, after learning that Stella (Miranda Rae Mayo) had gone to Oakland to vouch for him, proving just how much he brings people together, he was named the new Deputy Commissioner of the Chicago Fire Department.

Walker, who appeared in a total of 252 episodes of “Chicago Fire,” is the third series regular to exit this season after Alberto Rosende and Kara Killmer, who left in the first half of Season 12.

While the season finale seemed like it would end with the group hugging Boden goodbye, there was actually another secret waiting to be revealed. New firefighter Jack Damon (Michael Bradway), who has been keeping a secret since he joined Firehouse 51, came clean in the final moments. He revealed to Kelly Severide (Taylor Kinney) that the last call got to him and he lost his temper because he saw a father treating his son poorly. It hit close to home, he said, revealing his father treated him poorly — and that father’s name was Benny Severide.

Benny, who was portrayed by the late Treat Williams in 16 episodes, is Kelly’s father who died after suffering a stroke in Season 7.