The order of the millionaire merchant from Siberia was simple and clear - Maria, a girl from a poor noble family, the old man's unloved daughter-in-law, must give birth to his eldest son Fyodor an heir - or the rights to the family fortune will pass to his younger son, the reveler and gambler Pavel. However, Maria is barren, and then Lisa decides to help her twin sister and take her place...NO ONE notices the substitution of sisters - not even her husband, but vague suspicions torment Pavel, who has hated Fyodor since childhood...