This uneven comedy of manners concerns a young film projectionist (Jerome Ange) who sets out to find a marriageable woman. He sets his sights on two women he has lived with for nearly ten years (Kristin Scott-Thomas and Sylvie Orcier). For some reason, the projectionist encourages one of the women to hire a private detective (Patrice Kerbrat) to monitor his romantic activities.
Doctor Valois has invented the "flashage", a cure for depressed people. After having tested it on monkeys, he tries with a first human patient, Alain Durieux. This is great success, everybody's happy except may be Alain's wife, Jeanne, who's worrying about the changes in Alain's personality. Other patients use the treatment with similar successes, and Valois's happy about it. But the monkeys are changing: non-cured ones are made mad by the over-stability and stereotyped behaviour of the cured ones. So are the humans. When Valois realises he can't stop the process, he decides to "flash" himself.
Two great friends who practice cycling, Commissioner Servolle and real estate developer Faguet, see their friendship tested by the investigation carried out following the murder of Faguet's wife.
