Because of his great esteem in the village, Okonkwo is selected by the elders to be the guardian of Ikemefuna, a boy taken prisoner by the tribe as a peace settlement between two villages. Ikemefuna is to stay with Okonkwo until the Oracle instructs the elders on what to do with the boy. For three years the boy lives with Okonkwo's family and they grow fond of him, he even considers Okonkwo his father. Then the elders decide that the boy must be killed, and the oldest man in the village warns Okonkwo to have nothing to do with the murder because it would be like killing his own child. Rather than seem weak and feminine to the other men of the tribe, Okonkwo helps to kill the boy despite the warning from the old man.
Shortly after Ikemefuna's death, things begin to go wrong for Okonkwo and when he accidentally kills someone at a funeral ceremony, he and his family are sent into exile for seven years to appease the gods he has offended with the murder. While Okonkwo is away in exile, white men begin coming to Umuofia and they peaceably introduce their religion. As the number of converts increases, the foothold of the white people grows beyond their religion and a new government is introduced.
Okonkwo returns to his village after his exile to find it a changed place because of the presence of white men. He and other tribal leaders try to reclaim their hold on their native land by destroying a local Christian church that has insulted their gods and religion. In return, the leader of the white government takes them prisoner and holds them for ransom for a short while, further humiliating and insulting the native leaders. The people of Umuofia finally gather for what could be a great uprising, and when some messengers of the white government try to stop their meeting, Okonkwo kills one of them. He realizes with despair that the people of Umuofia are not going to fight to protect themselves because they let the other messengers escape and so all is lost for the Ibo tribe.
When the local leader of the white government comes to Okonkwo's house to take him to court, he finds that Okonkwo has hanged himself, ruining his great reputation.