Dominique, a young lady, inherits her uncle detective agency. She hires an enthousiastic and talkative young man, Robert, who claims to have some detective skills. A client knocks at their door : his wife received threat letters and he asks for their help.

Dominique and Robert infiltrate the Nostradamus Agency posing as clients in order to investigate the death of their client's wife.

Dominique and Robert establish their horoscopes for the agency. Another suspicious death is discovered.

Dominique and Robert return by night at the agency and discover a kill list in the Professor's office

Robert and Dominique confront the Professor. The death toll increases again.

Another couple rushes at the agency, Dominique and Robert discover some secrecies about the agency. Death strikes again.

Robert and Dominique disagree about who the killer is, they have to continue their investigation about the ir prime suspects.

Dominique and Robert unravel the true operation of the agency.

Dominique and Robert set a trap for the killer