After twenty-five years of marriage and twelve children, Ramatoulaye's husband, Modou, decides to take a second wife, Binetou. Being of the Muslim faith, Modou's actions are not out of the ordinary; however, Ramatoulaye is greatly hurt by his insensitivity. Modou also callously cuts off financial support and family ties with Ramatoulaye and their twelve children.
Ramatoulaye decides that she will work to support herself and the twelve children. She decides that it is useless to maintain an emotional or social connection with a man who willingly sacrifices his family's happiness for his own temporary satisfaction. After Modou dies of a heart attack, Ramatoulaye remains a single working mother. Despite offers of marriage from both Tasmir, her former brother-in-law, and Daouda Dieng, an old suitor, Ramatoulaye decides that she would be happier as a single woman. After suffering the shame and humiliation of being in a polygamous marriage, she does not want to be responsible for destroying the happiness of other women.
Ramatoulaye's friend, Aissatou, decides to divorce her husband, Mawdo, after he takes a second wife. Even though Mawdo really loves Aissatou, he finds himself the victim of tradition. Unable to endure the shame his mother would live under if he does not marry the young Nabou, Mawdo goes through the motions of a second marriage. Despite his desire to continue living with Aissatou after his second marriage, Aissatou decides that she cannot endure this humiliating arrangement. Eventually, she leaves Senegal with their four sons to start a new life in the United States.