An idol has been stolen arumbaya Ethnographic Museum and Tintin start your search. Following the clues, he discovers that two men are also interested in the same fetish. These men are aimed towards San Teodoro, a republic in South America. Ting follows them and is in the center of revolution. Through a series of coincidences ends become aide of General Alcazar. War breaks out between San Teodoro and the neighboring Nuevo Rico, Tintin pursued by all, fled to the territory of the arumbayas. There finally discovers the secret idol contains a small diamond. Finally, the fetish is recovered in Europe and returned to the museum.