Frank Villard portrayed once S.A.Steeman's detective Wens in "L'Ennemi Sans Visage " ,after Pierre Fresnay called it a day ;here he is a captain ,like Commissaire Maigret ,but the screenplay is not based on a Simenon novel;it's a Leo Mallet's book and the story,revolving around (a) diamond(s)is thoroughly worthless;as the title indicates ,it's just a pretext for letting us into the Folies Bergères ,the stage (two interminable acts) and the wings where a former star of the famous music hall(Dora Doll) hangs around:after a car crash ,she became lame and had to relinquish her career and thus is jealous of the new star played by Darryl Zanuck's protégée,ill-fated Bella Darvi . Darvi, after a part in Curtiz's "The Egyptian", was given lousy roles in poor B movies in France,like this dud .Her last movie was an erotic version of Comtesse De Ségur's "Les Petites Filles Modèles" (1971);soon after,she committed suicide .