A delinquent, the son of a police commissioner, leaves prison to seduce someone who should be like a sister to him: a girl raised and loved by his parents. To force her to give in to his obsession, he kidnaps her little daughter.
Daniel, a smuggler is chased by a policeman. In his escape are helped by the messages that his lover transmits to him in code by means of the tangos that sings in a radio program. To hide himself, he pretends to be a teacher in a small town in Entre Ríos, and by the time he discovers it, the police have already faced a new life.
Cars and progress made an old carriage-driver jobless and so desperate that he becomes a gangster. When his own son starts a life of crime, he repents and gives himself to the authorities. When he lives prison, he will be happy to rejoin his family, as his son repented, too.
