30 years ago, a woman gave birth to her fifth blonde-haired and blue-eyed baby, and brought home a dark-haired, black-eyed and seriously ill. All these years she was sure that her son was a stranger by blood. The mother of many children denies that she cheated on her husband, and believes in substitution in the maternity hospital. Did the mother of healthy children get her own or someone else's son?

A father with many children dreams of meeting an illegitimate son, about whom he has not known anything for 31 years. The man assures: the mistress recorded the child on the deceased husband, and then disappeared in an unknown direction. Only the son of that very woman declares that he knows exactly who his father is, and has never doubted his kinship with him.