When a nobleman is threatened by a family curse on his newly inherited estate, Sherlock Holmes is hired to investigate.

The ten-graders Gosha and Zosya are in love with each other. The last school waltz has been played and it seems nothing stands any longer in the way of the young people being together. However, getting the news that he’s going to be a father soon, Gosha chooses a “free life” and… marries Dina who has long been in love with him, though with no reciprocity. But already at the registry office, the lucky winner realizes that getting Gosha as her husband doesn’t mean getting his love, that unintentionally she made her loved one unhappy and they have no future together…