Severide finds that he shares a familiar past with Eric Whaley, the Lieutenant who was brought into the firehouse to help out. Dawson lets Shay in on her secret, while Casey deals with family issues. Meanwhile, a bad batch of heroin on the streets has Boden and the team scrambling, while Clarice and Shay find they have a new problem to overcome.
Elenco: Jesse Spencer , Taylor Kinney , David Eigenberg , Joe Minoso , Christian Stolte , Eamonn Walker , Yuriy Sardarov , Kara Killmer , Monica Raymund , Miranda Rae Mayo , Charlie Barnett , Lauren German , Annie Ilonzeh , Alberto Rosende , Dora Madison , Steven R. McQueen , Daniel Kyri , Hanako Greensmith .