Marian plays an engineer who is suspected of unfaithfulness by his girlfriend and so the lady secures the service of a detective agency to investigate about him. But as none of the regular detectives is available, the agency's boss (Oskar Sima) asks the young stenotypist Inge Christensen (Hielscher) to take on the job even though she is about to go on holiday with her fiancé. Anyway, the would-be detective follows the engineer on the night train, and soon seems to find the 'proof' she's looking for. Lots of hilarious situations ensue, but in the process the girl begins to like the engineer much more than she wants...

Very fast-paced comedy, exceedingly well written by Ernst Marischka. Marian is cast in an unusual role as a man who indulges in playing with toy ducks and other gadgets rather than having illicit affairs, even though he of course still has his usual wit and certainly made enough of an impression on Margot Hielscher. The two of them make for a wonderfully funny pair in this film with great chemistry between them. Marian and Hielscher would team up again the following year in Tourjansky's ""Dreimal Komödie""

But the verve of ""In flagranti"" makes it the better film, with a fine cast featuring Oskar Sima, Jane Tilden and other well known names, too. Add the catchy title song by Peter Kreuder, and you end up with one of the best screwball comedies of the second half of the Third Reich.