Nandi Bear is a richly woven tale that blends folklore, oral history and cultural memory into an allegorical narrative about change, identity, and survival. The narrative is a creative rendition of several Kenyan colonial figures' stories, specifically Koitalel Arap Samoei's, whose family was banished by the British to the Lambwe Valley for decades. It is set in the hills and plains of western Kenya, and the story follows Kwong'utiet, a warrior and family man, whose life intersects with ancient fears, colonial intrusion, and spiritual transformation.

At the heart of the story is the chemosit: a terrifying ogre also known as the Nandi Bear, feared for its haunting cries and habit of devouring human heads. For generations, the chemosit embodies both mystery and terror, symbolizing the fragility of human life and the boundaries between the living, the spiritual and the wild. Kwong'utiet's world is further disrupted when white strangers arrive, bringing bicycles, guns, and new religions. These visitors challenge the community's ancestral ways, offering a 'woman Creator' and a foreign future that unsettles local belief systems. Kwong'utiet's friend Hono embraces these changes, claiming miracles in his household, while Kwong'utiet wrestles with loyalty to tradition and curiosity about the new world.

The novel ultimately explores themes of cultural erosion, the clash of belief systems, the cost of survival, and the enduring struggle to reconcile ancestral identity with external influence. Through myth, history, and allegory, Nandi Bear illuminates the anxieties of a people caught between tradition and the modernity of colonialism.