Based on a novel by the prolific James Hadley Chase, this stylish, well-paced, B&W early 60s French crime film stars the handsome, athletic, and charismatic Sean Flynn as an American in Paris whose curiosity gets him sucked into an international intrigue that is not fully explained in the course of the film, but which is exciting and mysterious as it's happening (I watch films such as these for style, not logic). I'm not sure if Flynn is doing his own voice here--I'd say no, if that IS his real voice in Stop Train 349--but the voice assigned him is not off-putting, and he carries the film well with a boyish enthusiasm that reminds me of the young Jim Hutton. The effective shadowy photography and rapid pace are complemented by a fine jazz organ score by Alain Goraguer (whose work you can hear on volumes 1, 3, and 4 of the recent JAZZ & CINEMA CD series within the massive JAZZ IN PARIS reissue series). France produced many, many great b&w crime films in the late 50s and early 60s, many with great jazz musical scores. These are known in the US mostly from being shown on old UHF stations in the middle of the night or occasionally playing on the bottom half of the double bill at drive-ins and second-run theatres. Fans of dubbed 60s euro-crime films should enjoy this stylish outing. Also, anyone who wants to understand the appeal of the late Sean Flynn should check this out (and also Stop Train 349, in which he gives a fine performance opposite Jose Ferrer).