The Baroness de Courtebise presides over an association of mothers-in-law with grievances against their sons-in-law. Armed with her prerogatives, she forbids the marriage of her daughter-in-law to the mayor's nephew, especially as an inheritance is in doubt. The ladies kidnap, the men kidnap, the election campaign turns sour and the Baroness must capitulate. She takes revenge by falling into the mayor's arms.
Sherlock Coco, famous detective, tries to thwart the machiavellian plans of the trio of shock. Croquignol, Ribouldingue and Filochard must be extra vigilant, but the profit motive is too strong. As a corollary, the famous pink diamond is also of interest to their legendary enemy, Jo Papillon. But always inventive, they will work out multiple scams and tricks to reach their goals.
The struggles of a small business owner come to light in this film by director André Cayatte. The proprietor of a fabric shop, M. Baudu faces stiff competition when a department store moves in across the street, the first of its kind in 1860s Paris. On top of the stresses associated with the rival retailer, Baudu’s niece and two nephews take up residence with him after recently being orphaned. The niece, Denise Baudu, sees the writing on the wall for her uncle’s business so she takes a job as a shop girl with his competitor and despite her success the decision does not register well with the family.