Barney Miller - S1xE02 - Experience

Detective Fish is convinced he is too old for the job after a suspect outran him and wishes to retire, spending much of the episode dozing off and trying to hand in his resignation. Captain Barney Miller tries to talk him out of it. Meanwhile, the squad is investigating a "mad bomber" who is targeting public buildings. The bomber (played by Noam Pitlik, who would later direct many episodes of the series) calls the precinct and eventually leaves one of his bombs in a briefcase in the squad room, unbeknownst to most of the characters until near the end of the episode. The bomb provides a backdrop of tension to the usual precinct interactions and character humor.