Chicago Fire is bringing in a replacement for Dermot Mulroney amid the actor's hiatus from the show. News broke on Thursday, January 22, that Mulroney's Dom Pascal will be absent from the rest of season 14. According to Deadline, a story line that requires him to be off screen will be the way NBC writes the character off the show - for now. Mulroney is still expected to appear in the upcoming One Chicago crossover, which airs Wednesday, March 4, before Rob Morgan will take over.