Boden is on edge after starting a new fad diet. Casey and Severide disagree on a call. Brett's birth mother shares life-altering news. A familiar face has a proposition for Herrmann.
Cast: Jesse Spencer, Taylor Kinney, Kara Killmer, David Eigenberg, Joe Minoso, Christian Stolte, Miranda Rae Mayo, Annie Ilonzeh, Eamonn Walker, Kelly Deadmon, Giota Trakas