A film noir wrapped in an adventure tale, Ted Tetzlaff’s underappreciated Riffraff opens with an intriguing seven minutes free of any dialogue: two unconnected passengers board the cargo bin of a small plane during a violent thunderstorm, but, shortly after takeoff, only one remains. Everyman Pat O’Brien plays the Panama City private detective named Hammer (not that Hammer) hired to protect the remaining passenger, Charles Hasso (Marc Krah), as it seems Hasso has come into possession of a sought-after map of undocumented Peruvian oil wells which he just might have pinched from the now “missing” man. It seems everyone is after this map, including criminal Molinar (a fantastic Walter Slezak) and oil executive Gredson (Jerome Cowan), who assigns his girlfriend Maxine (Anne Jeffreys) to spy on Hammer, but, of course, she ends up falling for his rough-and-tumble charms. With a 20-year career as an accomplished cinematographer culminating in Hitchcock’s Notorious (1946), Tetzlaff continues to experiment with the camera in this, his directorial debut: slow zooms, keyhole closeups, innovative transitions. Slezak is a memorable and infantile villain who enjoys ordering his thugs beat Hammer to a pulp; note how Tetzlaff’s high angle shot of Slezak in his chair, which would normally make a character appear vulnerable, somehow makes his white, pudgy face even more intimidating. While the film offers plenty of adventurous fun, it’s also plenty dark and relentlessly violent in parts: the group fistfight in which Maxine weaponizes a bookcase is extraordinarily choreographed and viscerally bloody.