The man in the brown suit. Top-secret microfilms are stolen during a Russian ballet performance at Lille Opera. Aware that the troupe includes Soviet spies, the French Secret Service calls in Swan Laurence. He becomes the opera's new secretary, Brigitte.
Two murders are happening and the only witness there is is a dog. A castle is ravaged by ghosts who say they are going to reveal the name of the murderer. For Laurence, who doesn't believe in ghosts, this place stinks, especially now that her mother wants to get involved. As if that is not enough, her mother has also got it in her head to pair Avril, whom she loves, with her son. So a lot of headaches for the Commissione