"Fire" features the welcome presence of Steve Landesberg's Det. Arthur Dietrich from the 12th Precinct, dropping by for lunch before going out on assignment with Fish. Mike looks beat after a long night with the opposite sex ("from now on, I'm only going out with one at a time!"). Fish asks why he hasn't put on any clothes (Mike: "when I'm in bed, they tend to get wrinkled!"). Still dressed in his robe, Mike answers the door to find Sgt. Dietrich (Mike: "I've been in bed all morning!" Dietrich: "that'd be my guess!"). Meanwhile, Victor has become infatuated with lighting matches, so Charlie suggests he learn about responsibility by taking care of a pet. No one knows what Victor brought home in a shoebox (Bernice runs screaming from the room), so know-it-all Dietrich, with his vast knowledge on just about everything, is a cinch to identify it ("what the hell izzat?"). Officer Hutchins (Stanley Brock) appears to report on a deserted house two doors down in flames, identifying Victor as a possible firebug. Detective Dietrich expresses his admiration on how Hutchins handles himself professionally, telling him about a guy he used to work with that acted and sounded just like him (Hutchins: "oh yeah?" Dietrich: "partner shot him!"). In his lone appearance on this series, Steve Landesberg is a constant delight, making this a rare standout episode.