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.
A woman is told his military husband is considered dead, the truth is he has been transferred to the secret service. When he returns to Spain and they get reunited he ends killing a German spy, and then she gets prosecuted.
