Chief of the Copacabana precinct Espinosa is more than happy to interrupt his paperwork when a terrified young man arrives at the station with a bizarre story. A psychic has predicted that he will commit a murder, and the prediction has become fact in the young man's mind. It's a case more appropriate for a psychiatrist or philosopher, but there is something that attracts Espinosa to this case. As the weather changes and the southwesterly wind - always a sign of dramatic change - starts up, what at first seems like paranoia becomes brutal reality. Two violent murders occur and their only link is the lonely, clever man who has sort Espinosa out a few days earlier for help.