Chief Dom Pascal (Dermot Mulroney) is not in the best state of mind. The character lost his wife on the eve of their wedding anniversary, so we can't blame him much. A loss of that magnitude would traumatize anyone. The problem is, Pascal's trauma is resulting in dangerous calls being made in the field.
One of these upcoming calls will be so dangerous, in fact, that Pascal's precedessor, Wallace Boden (Eamonn Walker), will be brought in to investigate. Chicago Fire showrunner Andrea Newman talked about the dynamic of these two powerful men during a recent interview with TV Insider. She made it clear that they will not get along.
Boden and Pascal are headed for a conflict

"It's very fraught: Boden is heading an investigation into what went wrong during a tragic firefight that Pascal was in charge of," Newman explained. "So it’s contentious. Boden [will be] grilling Pascal about his every decision, and how things went as wrong as they did."
The contentiousness makes sense, given that Boden initially considered Herrmann (David Eigenberg) as a possible 51 replacement. He knows Pascal well enough, but it was evident from the beginning of season 13 that Pascal has a very different approach. These men do not see eye to eye on a lot, and it will result in some heated exchanges.
"[This] episode will define the relationship in some pretty emotional and complex ways," Newman added. The showrunner admitted that part of the reason behind killing off Pascal's wife was to push his character to the edge and see how the rest of 51 deals with it. The promo teaser for the March 26 episode makes it clear that there's widespread concern that Pascal has lost his good judgement.
Pascal is spiraling and 51 is concerned
Stella Kidd (Miranda Rae Mayo) describes the chief as "obsessive," and Herrmann asks Kelly Severide (Taylor Kinney) what should be done if Pascal doesn't snap out of his current funk. The fact that these questions will be raised before Boden even arrives says a lot about how precarious the situation is for Pascal and his future with 51.
There was some debate as to whether Dermot Mulroney would stick with Chicago Fire long term, or serve as a transitional chief between Boden and whoever takes the role over from Pascal. Mulroney is one of the biggest stars the show has ever had, and depending on how well his character rebounds following the Boden conflict, he may not make it to season 14. Enjoy Pascal while you can, is our suggestion.