L’Agence O is a famous Parisian private detective firm. Its premises are located in the Passage Choiseul. In front, Torrence leads the shop. In fact, the agency's team is complemented by Émilie le Roux, Mademoiselle Berthe and Barbet, who scrutinize clients through a one-way mirror located behind the desk. Getting hold of a man disguised as an old lady, solving the mystery of the Prisoner of Lagny or discovering who is blackmailing the painter Tigrane Alban does not worry the experts at the O Agency. Les Dossiers de l’Agence O is a French-Canadian television series in thirteen episodes of approximately 55 minutes created by Marc Simenon and broadcast first in Quebec from December 14, 1967 to March 13, 1968 on Télévision de Radio-Canada, then in France from March 11 to June 3, 1968 on the first channel of the ORTF.

In a little French town everything goes on as usual and people seem friendly and good-natured, until the day two women arrive from Paris. A man gets off the same bus, and that very night he seizes the two women and asks for the most beautiful woman in town as their ransom. After the initial shock, the mayor, his brother, the prefect, the police, and the gendarmerie gather around the house where the two woman are imprisoned. It will be a test for everyone and each of them will show his/her real stuff: hypocrisy, meanness, or humanity concealed under their provincial respectability.

The notorious and mysterious criminal Furax steals France's famous monuments, replacing them with replicas.

Victim of a traffic accident that costs her life, Laura, a call girl, resurfaces on Earth as an overwhelmed mother, Lucie.

A jewel thief hides his loot in a WELL while escaping. He returns several years later only to find there is a Resort on the site and the well is the centerpiece of the place. He then has to find a way to retrieve his haul.

A young physician becomes lonely when his workaholic wife ignores him to concentrate on her professional career. He is befriended by an older female artist who is fond of hallucinogenic mushrooms. When his wife is late for their anniversary celebration, he drinks and takes mushrooms with the artist. He wakes up to find she has died and is fearful he may have accidentally killed her.