Madeleine Villardier is terribly superstitious, and she's in a lot of trouble for the New Year's Eve party she's planning. Inexorably, the number of guests is down to thirteen. To add to her dismay, the presence under her roof of a certain Consuelo is proving cumbersome, especially as this lady has revelations to make about Antoine Villardier's stormy past. The mistress of the house's trances alternate with marital explanations. But why not consider the fateful number as a lucky charm?
Suzanne is a lawyer, she's just got her degree and she is married to a cop. We follow her through three investigations.
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.
Rather than commit suicide, it is better to stay at the clinic of Professor Patureau-Duparc. This practitioner experiments on his clients with a serum that modifies their personality. Thus Yolande and Albert become new Romeo and Juliet. They end up marrying each other after having regained their primitive selves. Their married life is then a hell and they welcome with joy the proposal of a new injection of serum.
When Monsieur Crauqual, the supervisor, is found hanging, all wonder why this rather rich person decided to kill himself. And when a pupil is found hanging too, François and his friends decide to investigate. They are certain there is a killer within the walls of Collège François 1er and determined to prevent him from going on running wild.
When she sets sail for Lisbon, Catherine Laurence, a famous classical singer has but one wish: to be left alone. Unfortunately she soon gets bothered by a rude, invading man. Later she gets to know him better and becomes susceptible to his charm. She realizes that Michel is in love with her and it is not long before she goes beyond her disastrous first impression. Although not quite sure he is a perfectly honest man she entrusts him with a delicate assignment: keep her precious pearl necklace coveted by Van Coolart, a fake Dutch diamond-merchant, and give it back to her in Paris. If he is a robber himself, so much the worse for her. But if Michel keeps the Paris rendezvous love is in store for both of them. Nevertheless there is a crucial factor she regrettably disregards, composer Raymond Aubour, a faithful friend who has been her suitor for ten years.