Barcelona, Spain. A young man is murdered in the middle of the street in front of the police headquarters. Miguel and Marcial, two agents of the Criminal Brigade in charge of the investigation, find in the victim's room a newspaper where a cryptic classified ad appears.
Conrado San Martín
as Miguel
Elena Espejo
as Carmen
Tomás Blanco
as Antonio
Manuel de Juan
as Marcial
Luis Pérez de León
as Don Rafael
Carlos Muñoz Arosa
as Rafael
Guillermo Marín
as Eyewitness
Casimiro Hurtado
as Pascual el Mirada
Emilio Fábregas
as Police Commissioner
Eugenio Testa
as Julián Azores
Marta Grau
as Doña Lola
José Goula
as Postmaster
