Rex Rivetter: Private Eye is a serialized noir audio drama from Downstairs Entertainment, set in 1955 Los Angeles. The detective does the talking. Fourth-season episodes all open the same way, with an announcer noting that it is Monday night and addressing the ladies and gentlemen. Those openings also carry a practical warning: the season builds on characters and plot lines from earlier episodes, so newcomers are told to go back and catch up. The advice is worth taking, because the back catalog is sizable and the threads carry over. Once the announcer steps aside, Rex narrates in the first person, and the prose is unapologetically pulp. After a blast throws him against a wall, pain 'dances the merengue.' Money comes in clams and dough. He can't settle whether his client is Marion Julius Page or Julius Marion, and he jokes that the only difference is where the air quotes go. In 'Deadlier than the Male', that client receives a ransom note for his girlfriend demanding 7,500 clams by the following night. Rex's run-ins with the police are pure patter. He insists on spelling his name for a cop, one V, two R's and two T's. When he is threatened with a 459 booking, he points out that it means a lot of paperwork for them. At another point he stands with his back against a warehouse wall, with a hearing that someone named Burke has promised him still ahead, when a figure he knows by its rat face appears in silhouette in the doorway. 'The Final Farewell' is darker by a wide margin. It is announced on air as the season four finale and comes with an advisory for graphic violence and torture, and it runs without commercial interruption. Its closing chapter gives first-person passages to a killer who savors the fear of a captive named Jenny and admits the Millers were murdered as a way to reach someone else. The music stays in period. The Artie Shaw Orchestra's 'Nightmare' serves as Rex's theme, and Jenny has one too, 'Softly, as in a Morning Sunrise.' Then the period spell breaks. Several episodes cut to modern, pandemic-era comic spots in which a bantering pair talks up takeout from a Black-owned brunch spot in San Diego's Hillcrest, handmade soy candles from a female-owned Los Angeles business, a free radio musical of 'How the Grinch Stole Christmas', and help for theater artists left out of work. The jump from a warehouse standoff to holiday decorating plans is abrupt. The credits name Steve Murdock for editing and sound design, and Greg McAfee signs off for Downstairs Entertainment. The finale's closing promises a return for Season 5 in 'Hooray for Hollywood.'