The novel follows the story of a modern black American man who is able to mentally project himself back to pre-human Africa, where he meets (and eventually mates) with humanity's prehistoric ancestors.

Since the very beginning of his life, John dreams of an ancient world and becomes an expert of the Pleistocene epoch, the era of the Homo habilis in Africa.

[1] Almost lost in the remote past of a world which is the frontier between non-human and human life, John/Joshua feels he has reached the reality he always belonged to, and is accepted by a group of individuals who live in the African savanna.

Back to his actual life, Joshua finds he lost his dreaming power and learns that only a month in modern world's time has passed since he left; this is why he struggles in being believed about his daughter.

[1] After several years Joshua becomes a minister of the Zarakali government, and his 15-year-old daughter escapes with an agent from Uganda, Dick Aruj, who has convinced her to join a program of time travel to the future.