A single mother calls her 7-year-old daughter's father a former lover who is 18 years older. The man also considers the girl's father to be another lover of a woman who was 19 years older. But the neighbor insists that the woman had even more lovers.

For eight years now, the whole Ponomarev family has been living on pins and needles. The grandmother and grandfather doubt three grandchildren, the father doubts two children, and the mother herself doubts only one son. So which of the three children bears the surname Ponomarev by right of birth, and not only by documents?