(uncredited)
Back from a stay in the Far East, a woman who knew the names of the chiefs of a drug ring is murdered. Georges Masse, the famous reporter, decides to investigate, accompanied by his faithful photographer P'tit Louis. He will come across some unappetizing characters like M. Dubois, a killer, Luigi Costelli, a dangerous trafficker and a beautiful but dubious lady, Suzanne Wilson. After being himself suspected, Masse will make the truth triumph.
Maurice Vallier, nicknamed "Ma Pomme"(which means "myself" in slang), is a cheerful man, well aware that money does not make happiness and who, of all things, prices freedom. Which is why he has become a tramp and he has never regretted his choice of life. Things go smoothly until the day he inherits a huge amount of money. He first refuses it but changes his mind when he realizes that thanks to the inheritance he can help others. Even more enticing is the fact that he must share the big money with a charming air hostess. However once he deems he has done enough good he gives up the money left and resumes his old lifestyle singing along "Ma pomme c'est moi, j'suis plus heureux qu'un roi..."
For the Marquis Barbezieux de Saint-Rosay, nobility is important. If anything can comfort her, it's her family tree. In order to erase any doubt he invites in his castle a cousin of his established in Scotland, whom he instructs to bring him his titles of nobility. A first person introduces himself, calling himself his cousin, but it's not him. Then one, then two, then three false cousins appear in turn. Will the real Saint-Rosay of Scotland eventually present itself?
Durand, a big industrialist, works with an international adventurer, Mr. Ernest, who covets Mrs. Durand and threatens to bankrupt her husband if she does not consent. She calls him a jerk. Mr. Ernest sets out to ruin the Durands, and leaves in the castle that they must sell their couple of servants, Victor and Marie, who become the new masters, at the same time as they serve as a screen for Ernest for his dubious business.
(uncredited)
In Paris, three models are murdered, being one of them the mistress of the fashion designer Dominique Airelle. It is the young inspector who is in charge of the affair.
