Nnu Ego, the protagonist, stumbles across the Yaba compound, almost delusional with grief. She makes her way to the waterfront, heading to Carter Bridge, intent on throwing herself off.
The action shifts to twenty-five years previous to this moment, in the village of Ogboli in the Ibuza homeland. Agbadi, the esteemed local chief, is enamored by the one woman he cannot possess, the beautiful and strong-willed Ona. During a hunting trip, Agbadi is gored by an injured elephant and not expected to live long. Ona slowly nurses him back to health. As he heals, he humiliates her in the compound by loudly forcing his sexual attentions on her. She becomes pregnant as the result of this union. If it is a boy, the child will belong to Ona’s father, but if it is a girl, Agbadi will accept responsibility. When Nnu Ego is born, a medicine man concludes that her chi, or guiding spirit, is the slave girl who was forcibly killed and buried with one of Agbadi’s wives. Within the year, Ona dies during childbirth.
Sixteen years later, Nnu Ego is of marrying age. She is first betrothed to Amatokwu. When she does not become pregnant, relations cool between her and Amatokwu, and she is soon moved to another hut to make room for a new wife. Nnu Ego is relegated to working in the fields and taking care of the new wife’s infant son. When Amatokwu catches Nnu Ego breast-feeding the hungry child, he beats her. Nnu Ego returns to her father to rest and recover, and the marriage ties are severed. Dedicated to finding his daughter a better match, Agbadi arranges a marriage between Nnu Ego and Nnaife, who lives in faraway Lagos. Nnaife’s older brother escorts Nnu Ego to the city and her new life with Nnaife.
Nnaife and Nnu Ego live in the Yaba compound, where Nnaife does laundry for the Meers, a British couple. Happy in her marriage, Nnu Ego becomes pregnant and gives birth to a son, Ngozi. She also starts her own business selling cigarettes and matches beside the road. One morning, she discovers Ngozi dead in their one-room home. Distraught and devoid of hope, she rushes to the waterfront to throw herself off Carter Bridge. Nwakusor, an Ibo man coming off his shift at work, prevents her with the help of the crowd that has gathered.
Recovering from Ngozi’s death is a slow and painful process. Eventually, Nnu Ego becomes pregnant again and gives birth to Oshia. She decides to focus solely on raising the child instead of making extra income at her market stall. But economic pressures set in when the Meers return to England and Nnaife is suddenly out of a job. Nnu Ego resumes her local trade in cigarettes. Nnaife eventually secures a position that takes him far from home, working for a group of Englishmen. While he is away, British soldiers enter the abandoned compound and tell Nnu Ego that she and Oshia must vacate the premises. Nnu Ego takes a rented room in another part of town, where she gives birth to another son, Adim. Left on their own, the family slowly succumbs to malnutrition. Neighbors step in to help. Nnu Ego returns from her search for more contraband cigarettes to find that her husband has returned, flush with money. Nnu Ego secures a permanent stall in the marketplace and pressures Nnaife to find his next job.
One evening, Nnaife’s friends arrive with the news that his brother has died in Ibuza. Nnaife has inherited all of his brother’s wives, but only one will come to live with them in Lagos. Adaku arrives with her daughter, setting off tensions and rivalry between the two women. As Nnu Ego tries to sleep nearby, Nnaife invokes his rights as a husband and has sexual relations with Adaku. Nnaife starts a new job cutting grass for the railroad. With less space and more mouths to feed, Nnu Ego and Adaku become pregnant around the same time. Nnu Ego gives birth to twin girls, while Adaku’s son dies shortly after he is born. Feeling they are not being given enough money to support the household, the women go on strike. Nnu Ego’s firm resolve eventually wavers, and she cooks a large conciliatory meal. But Nnaife does not come home to enjoy it. He has been forced to join the army and is shipped off to India and then Burma to fight in World War II.
With Nnaife away and his pay partially secure in a savings account, Nnu Ego, again pregnant, takes her family to Ibuza and to the deathbed of her father. After his two funerals, Nnu Ego is unwilling to return to Lagos. However, Adankwo, the eldest wife of Nnaife’s older brother, urges her to return to the city to keep an eye on Adako. Nnu Ego returns to find that Nnaife had been home for a brief visit and had left some money for her that she failed to receive. Relations between Nnu Ego and Adako grow increasingly strained, culminating in Nnu Ego’s rude and brusque treatment of one of Adako’s visiting cousins. When Nnaife’s friends step in to resolve the conflict, Adako decides that she and her daughters will move out on their own. Impoverished once again, Nnu Ego spends the last of her savings before learning she had not been receiving her husband’s yearly stipends due to an institutional error. Nnaife returns and spends most of this windfall. Though Nnu Ego is pregnant again, Nnaife decides to return to Ibuza, where he impregnates Adankwo and returns with a teenage bride, Okpo. Nnu Ego gives birth to twin girls.
The family moves to a mud house in another part of town. First Oshia and then Adim announce their intentions of furthering their educations. When Oshia tells Nnaife he has won a scholarship to study in the United States, Nnaife denounces him for his dereliction of his filial duty. Taiwo’s marriage is arranged to an Ibo clerk, but Kehinde runs away to marry a Yoruba. Hearing the news, Nnaife flies into a rage and attempts to murder Kehinde’s father-in-law with his cutlass. Nnaife is put in jail, tried, and sentenced to five years, a stint that is reduced provided he return to Ibuza after his release. Nnu Ego has also returned to her homeland, where she dies several years later, alone by the roadside. Oshia returns to honor Nnu Ego with a costly funeral, befitting her sacrifices as a mother.