Lt. Severide has his strong ideas on who the serial arsonist is, but first needs to find proof to back up his suspicions. Meanwhile, Lt. Casey adjusts to his new lifestyle in the wake of recent events and Mollys bar is failing, much to the dismay of owners Hermann, Dawson and Otis. Elsewhere, Dawson goes out on a date with Jay Halstead, one of the bar regulars, and Mouchs campaign trail starts to get on track with the aid of Isabella, an old friend of Dawsons.