Copacabana, Rio de Janeiro. Three policemen have been killed over the course of a few days. Espinosa, chief of the 12th Precinct, doesn't have much to go on. When the body of a woman connected to one of the dead cops is found on the sidewalk below her apartment window, things get even more complicated, as a reputed "witness"--the wife of a high-ranking government official--becomes obsessed with the case, and with Espinosa.