S2, E19: A suicide note is delivered to a surprised Dawson (Monica Raymund) and Lt. Severide (Taylor Kinney) digs deeper into Bloom's (guest star W. Earl Brown) dark past. Elsewhere, Chief Boden (Eamonn Walker) learns shocking news, and with the help of Shay (Lauren German), Lt. Casey (Jesse Spencer) goes on the search for a life-changing item.