Suzy Delair is the eponymous songstress, married to her unassuming accompanist "Maurice" (Bernard Blier). Now she is from a grittier background than her well-to-do husband, and she is ambitious - so when he catches her eying up elderly, and rather seamy, businessman "Brignon" (Charles Dullin) he loses his temper. When he subsequently discovers that she has gone to meet him, "Maurice" heads to his home with blood in his eyes. Thing is, when he gets there the corpse is all ready and waiting for him. Whodunit? Well that's down to the ferret-like skills of "Insp. Antoine" (Louis Jouvet). The plot ...