SPOILER ALERT: This story contains major details from the Season 15 premiere of Chicago Fire. Firehouse 51 is officially entering a new era. Dermot Mulroney made his final appearance as Battalion Chief Dom Pascal in the Season 15 premiere of NBC’s Chicago Fire, ending a two-season run that began when the veteran actor stepped into the considerable void left by longtime series star Eamonn Walker.
And while Pascal’s departure had been expected, the premiere makes clear that the bigger story is what comes next. For the first time in the show’s 15-season history, Firehouse 51 will move forward without a chief stationed in the house.
Instead, Taylor Kinney’s Kelly Severide will take on a larger leadership role.
New showrunner Victor Teran told Deadline that Mulroney’s character served as an important bridge between the Boden era and the show’s next chapter. Pascal’s final appearance was limited to the premiere specifically to create room for Severide to step forward.
It is a significant shift for a series that has historically anchored Firehouse 51 around a strong chief.
Boden filled that role for the show’s first 12 seasons before Walker stepped back as a series regular. Mulroney joined in Season 13, initially arriving as something of an outsider before gradually earning the trust of both the house and the audience.
Pascal’s tenure was much shorter, but his exit allows the show to alter its internal structure rather than simply replacing one chief with another.
In the Season 15 premiere, Severide chooses the leadership position at 51 over a separate inspector opportunity. That does not mean he is completely abandoning investigative work.
He continues to quietly operate in that world while trying to help Joe Cruz, played by Joe Miñoso, clear his name after accusations tied to the Season 14 fire.
That creates immediate tension for Severide, who is now balancing the responsibilities of leading the firehouse with the instincts that continue to pull him toward investigations.
Pascal’s final contribution is a warning.
Before leaving, he cautions Severide about trying to straddle those two worlds, suggesting that the consequences could become serious if he is not careful.
It is a fitting final beat for a character whose own arrival at 51 was defined by questions about authority, trust, and leadership.
Mulroney’s departure had been announced over the summer, although early reports suggested he might appear in multiple episodes at the beginning of Season 15. The premiere ultimately became his final episode as a series regular.
Mulroney has made clear that he valued his time on the series.
Speaking previously about his exit, the actor praised both the cast and crew and described his two seasons on the show as a rewarding experience. Deadline also reported that Mulroney said leaving was “bittersweet.”
The door may not be permanently closed.
Chicago Fire has a long history of bringing familiar faces back after their regular runs have ended. Eamonn Walker, for example, returned as Boden for a guest appearance after stepping away from full-time status.
So Pascal could conceivably return. For now, however, the focus shifts squarely to Severide. That may be the most interesting part of the change.
Severide has always been one of the show’s strongest firefighters and most instinctive leaders, but he has rarely been placed in a position where the entire house effectively looks to him.
Season 15 changes that.
Mulroney’s Pascal may have been brought in to follow Boden, but his real legacy may be helping Chicago Fire move from one era to another.
And now, for the first time, Firehouse 51 belongs to Severide.
