Polygamy.

A rich man has two wives and two brothers-in-law, each of them related to one of the wives. When he decides to go to England, he takes his first wife's brother with him. During his absence, his second wife, with the help of her brother, treats the first wife badly, eventually trying to get rid of her after she gives birth to a baby boy. The first wife, to save herself and her baby from being burnt, is forced to leave the house.