A mysterious creature appears in the Mandinka Kingdom of Kaabu, claiming the lives of many people. In such a highly superstitious kingdom, its appearance and claim to numerous lives leaves everyone thinking that it is not ordinary for such a creature, which their ancestors never knew to appear in the kingdom.

Numo, the protagonist of the story, and his brother Arfang get lost in the forest, prompting the entire village of Passamarey to prepare an army to search for them. After being found unhurt, their mother, Manke, is severely admonished for allowing the situation to unfold, putting the lives of the entire army at risk.

Years pass, and Numo and Arfang grow older. The creature continues to kill more people.

One day, during a hunting expedition, Numo and his brother, along with their father, come across a stinking human carcass - a man killed and desecrated by the mysterious creature. Numo makes a resolution to kill the creature when he grows up.

The following chapters depict various rituals and festivals that illustrate a typical Mandinka society before colonialism. After Numo and his brother are circumcised and initiated into manhood, circumstances change, but Numo remains resolute on killing the creature.

Finally, the great marabout of the land calls upon Numo and his brother, Arfang, and reveals that they are destined to kill the creature - actually a human being who transforms into a creature as a form of vengeance against the king of Kaabu for disrespecting her. Numo and Arfang are prepared by the marabout and set off on their journey.

After a long and tiresome journey, they encounter the creature and finally kill her, but on her own terms. .