Fire investigator and former legionnaire Jean Sarre is called to the scene of an accident and discovers that the wrecked car was not involved in an accident at all, but was the target of an arson attack. This is the beginning of an investigation that takes on ever greater proportions. The involvement of a not always very diligent detective, a corrupt building contractor, several petty criminals, an unscrupulous doctor, and some gorgeous women makes for an explosive mix!