Herrmann is tormented by a difficult decision; Casey is thrown into the spotlight at a fundraiser; Dawson and Brett are faced with the repercussions of their actions; Severide helps with a case regarding homemade explosives; Otis is surprised.
Dawson asks Severide for help; Brett and Kidd compete for Zach's heart; Otis, Herrmann and Mouch try to figure out the source of a terrible stench wafting throughout the firehouse.