Manelik (Pedro Armendáriz) is a poor shepherd who lives alone in the countryside. He will do anything to protect his lambs, even killing a wolf with his own hands, which has attacked one of the animals. One day, a rich corn merchant, who owns a mill, comes to visit Manelik with a beautiful woman (Zully Moreno), proposing him to marry her. The woman doesn't know about the Maquiavellian plan either, involving her father as well. As a matter of fact, she's the merchant's fiancée and will have to participate in the plan if she wants to stay with him. Manelik gets fascinated with the woman's beauty, whom got married despite her resistance to the wedding. Some time later, Manelik becomes a well respected man and an experienced corn merchant, working in the mill with the nasty man as his master. During the nights, the man visits the woman, hiding from Manelik. However, the woman starts to have feelings for Manelik, despising her fiancé because the plan has gone to far.