A lackadaisical handyman and aspiring novelist tries to support his younger girlfriend as she slowly succumbs to madness.

Jules, a young Parisian postman, secretly records a concert performance given by the opera singer Cynthia Hawkins, whom he idolises. The following day, Jules runs into a woman who is being pursued by armed thugs. Before she is killed, the woman slips an audio cassette into his mail bag...

The series follows the adventures of lighthearted Jean-Paul Moulin, a police Commissaire, and his team as they solve crimes.