Fascinated by the history of his people, Alloune, an old guide at the African museum "La Maison des Esclaves" in Gorée, sets off on a pilgrimage to find the descendants of his ancestors in the United States. This moving journey takes him from the coast of South Carolina to the Harlem neighborhood of Little Senegal, home to the African community. Driven by the idea of reuniting his family across centuries and borders, Alloune traces his roots to a distant cousin, Ida, who knows nothing of his past. The old man also crosses paths with his nephew Hassan, a clandestine cab driver, his fiancée Biram, Eileen, pregnant and a runaway, and Karim, who is seeking a sham marriage to obtain a green card. All four misunderstand Alloune's quest.

On 2 January 1899, starting from the French Sudan, a French column under the command of the captains Voulet and Chanoine is sent against the black Sultan Rabah in what is now the Cameroon. Those captains and their African mercenary troops destroy and kill everything they find on their path. The French authorities try to stop them sending orders and a second troop but the captains kill the emissaries who reach them. Sarraounia, queen of the Aznas, have heard about the exactions. Clever in war tactics and in witchcraft, she decides to resist and stop those mad men.