In a universe nine generations removed from the world of the Fifth Prophet and the founding of the Family of Man, a Martian genealogist develops a series of ancestral portrait simulations. Although he is obsessed with the past, the ever changing future intrudes on his simple artistic life and brings him an epic poetess to love, a mystic quest to follow, a cosmic battle to fight to the death, and salvation. Uniquely qualified by a mental mutation, he stands as Janus, a bridge between the past and the future of mankind. As he hunts for answers to unexplained temporal anomalies, he is pursued through this imaginative cosmology of static universes and infinite possibilities by an alien devil.