Nora Gregor is a cabaret singer who gets a kick out of stealing gemstones. Gustav Fröhlich runs a perfume shop, and his expertise with scents helps clever-stupid police detective Peter Lorre track her down, while his supervisor, Otto Wallburg, bumbles along. Kurt Horwitz is the fellow who stops Miss Gregor from being arrested by following her around and paying the jewelers for the stones she's just stolen. Obviously he wants her, but Fröhlich and Miss Gregor are in love, and they believe that love will keep her from stealing.
It's a musical comedy, with a couple of songs. Lorre gets into a duet with Miss Gregor, singing a song about how all the girls love policemen; his piano-faking is awful. There are a couple of big production numbers towards the end, but once Lorre stops getting stuck in the handcuffs he's invented, not that many good jokes.