1889. Ugo Pastore, a young man who went to Africa on the wake of his father, a businessman for big Italian company Caput Mundi, takes part as a consultant in the peace treaty between Italy and Ethiopia. At the last minute, Ugo realizes that the Italian and Amharic versions of the agreement differ in a key paragraph. Hes unable to have the treaty modified, though, and become convinced that the error possibly not accidental at all will spur fatal controversies. Subsequently assigned to an expedition to Sudan, the young man is captured by the marauders who follow Volto Nascosto (Hidden Face), an enigmatic warrior prophet that Ugo already met in Massawa. Volto Nascosto allows Ugo to go free, provided he warns the Italian authorities regardless of the path Ethiopian Emperor Menelik II will choose, Volto Nascosto and his marauders will keep on fighting against the Italian troops.