The Russian melodramatic series "Rainbow in the Sky" tells the story of a young couple named Katerina and Vadim. They are deeply in love and dream of starting a family together. However, it seems that fate is against their happiness. Vadim's younger brother has committed a crime and risks ending up behind bars. Their mother threatens to take her own life if Vadim doesn't find a way to save his brother. He is forced to leave Katerina and enter into a marriage with the daughter of the local administration chief.