In the wake of Heather's incident, Lt. Casey is having a hard time handling his newfound responsibilities. Lt. Severide is on edge dreading the next attack from the firehouse's arsonist. Meanwhile, with Renee back from her mother's, Severide knows he... (more) has to confront her about his paternity suspicions. Elsewhere, Mouch begins his campaign for union president and Shay and Dawson feel that they need to get out more.

Chaon Cross, Jeff Hephner, Jesse Lee Soffer, John Hoogenakker, Jon Seda, Larisa Polonsky, LaRoyce Hawkins, Linda Powell, Michelle Forbes, Sarah Shahi, Tim Hopper, Treat Williams