1892. Under the reign of Napoleon IV, the French Electric Empire sets out to conquer Africa. Thanks to France's technological prowess, its colonization of land and people quickly brings it to the heart of the continent. But devastating waves of electricity suddenly sweep down the River Congo, spreading death and threatening the triumphant advance of the Europeans.

Two special agents, a black colonial army officer who has been rejected by his own people, and a softie journalist as pious as he is careerist, are assigned to travel up the river to discover the origin of the disaster. They are soon confronted with the brutality of colonialism and the horrors of the jungle.