The story begins with Tintin coming to Marlinspike where it is reported by Captain Haddock Bianca Castafiore has begun a tour of San Theodoros (The broken ear), the country's ousted General Alcazar. The next day, Tintin, Haddock and Professor Calculus learn that Bianca Castafiore, her maid Irma, her pianist Wagner and detectives Thomson and Thompson were arrested on charges of conspiracy to defeat General Tapioca (current ruler dictator of San Theodoros) and including three (Tintin, Captain and Calculus) are accused of planning the operation.
Tintin, Haddock and Calculus traveling to San Theodoros to meet with General Tapioca who retains them without making them prisoners. During the course of a tour of an Aztec pyramid, organized so that Tintin is "rescued" by General Alcazar, are victims of a betrayal of Paul (The Broken Ear) who tries to help tapioquistas to abolish a the four friends. Tintin realizes this trick and get get everyone out alive after which head to the camp of the Rogue guerrillas commanded by General Alcazar.
Once in the camp of Alcazar and his guerrillas Rogues, patents are the few chances of success of the coup that intends to carry out General Alcazar, because their soldiers are permanently drunk (due to the boxes of whiskey Aircraft are generally released Tapioca). Tintin manages to convince the General Alcazar to make a revolution without bloodshed and in return he'll keep his men were drunk. Using a new invention of Professor Calculus producing alcohol intolerance (and has been tested by Captain Haddock without him knowing) manage Alcazar's men can not taste the alcohol.
When planning the coup, there is a bus full of Belgian artists lost (the Merry Turlurones) led by Seraphim Brass to participate in the festivities of Tapiocápolis. Using the same costume the group of artists find their way into the capital and seize power. It is found that the brains behind the falsehood is Colonel Sponz (The Calculus Affair).