Tracy Spiridakos and Jesse Lee Soffer are finally returning to Chicago P.D. after their respective exits led to Upton and Halstead's shocking split. NBC announced on Wednesday, February 4, that Spiridakos, 37, and Soffer, 41, are reuniting in the three-part One Chicago crossover special. According to the synopsis for the Wednesday, March 4, episode, Upton "returns to her former stomping grounds, but this time on the federal level as a Special Agent of the FBI." She "joins her former P.D. allies after a drug enforcement task force case out of her Detroit field office leads her back to Chicago.