Free-lance undercover agent Coplan receives a phone call from an old girlfriend in Turkey. The panic-stricken woman gives sketchy details of a plot that threatens world security. When Coplan arrives, he is told the woman has been killed, and the trail of the murderer leads to her mad-scientist brother.

In this French murder mystery, a young journalist goes from a bad situation to much worse. He has been having problems in his relationship with his girlfriend, and one evening he goes out on a bender. Too drunk to remember how he got that way, he goes home to sleep it off. When he wakes up in the morning, he discovers that his hangover is the least of his problems -- he is now a suspect in a murder investigation. After getting back together with his girlfriend, he decides to hide out with a friend of his and let the heat cool down -- a big mistake, as he soon finds out.