Arguably, every genre contains elements of most every other if you look deeply enough into film history. Film noirs can have musical numbers (e.g. Gilda, 1946), take place in the 19th-century (e.g. Gaslight, 1944), and even feature rural settings (e.g. The Red House, 1947). So why not humor? The most obvious answer, of course, is because film noir is all about mood. Even with musical numbers or happy endings, film noir is serious business. From its origins in German Expressionism to its relationship to hard-boiled crime fiction, film noir served historically to address cultural anxieties in the post-WWII years and into the Cold War. Its characteristic darkness and violence—both physical and emotional—make its tone antithetical, or at least hostile, to comedy.

But for every rule there is an exception or two, and this is true of film noir and humor. The 1955 noir Shack Out on 101 features a Cold War plot about selling nuclear plans to the Soviets as well as moments that are not only funny but downright wacky. We might not expect this in a film starring Frank Lovejoy, Keenan Wynn, Whit Bissell, Lee Marvin, and Terry Moore. Nor is does it logically proceed from being written and helmed by B horror and science fiction director Edward Dein—of The Leopard Man (1943) and The Leech Woman (1960) fame.

In part because (a very young) Lee Marvin’s character “Slob” is masking his criminal identity, he plays the fool until the final moments of the film. This accounts for his wisecracking persona and stunts like pretending to strangle himself to make a point. It does not, however, explain the moments of bizarre comic relief in the picture. For example, Slob and diner owner George (Keenan Wynn) do 98-pound weakling impersonations as they lift weights together in the middle of the diner, hoping to impress women with their (largely absent) muscles. This leads to an even more ridiculous lovely legs competition, where waitress Kotty (Terry Moore) is asked to choose whether George or Slob has the best calves. (She raises her skirt to claim the victory herself.)

The film’s most uproariously (or egregiously) slapstick moments emerge through a subplot about shell-shocked diner regular Eddie (Whit Bissell), who needs some serious rest and relaxation. George plans a deep-sea fishing trip for the two with all the necessary accouterments. The two try on flippers, masks with snorkels, and even a harpoon gun. George repeatedly performs pratfalls, Kotty laughs and tells the men they look like aliens, and Slob groans and rolls his eyes. Finally, the duo harpoons the huge trophy fish on the wall, which is wired with red electric eyes. Upon being pierced, it smokes and sparks and makes terrible noises. In practical, plot-relevant terms, all of this chaos serves only to alert the audience to the presence of the harpoon gun that will help save the day in the end.

As I hope is clear, broadly comic elements are a terrible addition to film noir. Cutting the tension as occurs so broadly in Shack Out on 101 is a bad plan for a genre/style that relies on tension. This late-cycle low-budget film—with is poor pacing and thin plot—needed something to help it stand out, and stand out it certainly does, but more for campy fun than for noir relevance.