La Java du Privé (1985)

The husband of a wealthy banker—neglected and vaguely paranoid, influenced by a television series—is convinced that his wife is cheating on him. He has contacted a specialized adultery agency, which quickly uncovered his wife's incriminating activities. Having heard of your excellent track record as a private detective, the wife now begs you to help her cover up the evidence and save both her marriage and her social standing. As luck would have it, you’re currently at odds with the local crime boss, who’s given you a choice: leave the country within 24 hours or end up as fish food in the Seine. Will you manage to complete your investigation? Who can you trust to help you? It’s up to you to find out—before it’s too late...