There's been a rash of fires plaguing Chicago, generally arson to claim insurance. Two brothers are shown setting a factory fire (James Coburn and Leonard Nimoy). The younger brother (Nimoy) kills the night watchman, angering his sibling as no one was supposed to get hurt. Frank investigates, driven by pity for the widow of the night watchman and looks for the arsonists in a local folk club. (thetvdb.com)