Is Каинова печать coming back?

Liza and Valentine found their happiness in the declining years. She is a widow, he is divorced, both have grown-up children. The new family lives in peace and quiet, even half-brother and sister - against expectations - get along well with each other. And then a young man appears on the threshold and says that he is the son of Liza's late husband. On the family council, the new son is decided to shelter and warm. From this moment the life of the family changes irrevocably. And after a while in the city there is a murder. Lisa can not admit to herself, whom she suspects of this crime ...