Eamonn Walker, David Eigenberg, Joe Minoso, Jesse Spencer, Christian Stolte Photo

From: Photo Flash: CHICAGO FIRE's 'Nazdarovya'

On CHICAGO FIRE's upcoming episode, titled 'Nazdarovya,' Dawson (Monica Raymund) attempts to help her brother Antonio (guest star Jon Seda) unravel the details of his drugs-and-gang investigation, and goes behind his back in turning to an unlikely source for assistance. Casey (Jesse Spencer) and his mother, Nancy (Kathleen Quinlan) struggle with their new relationship.