All over the country motor vehicle engines are spontaneously exploding. The cause for this is narrowed down to the type of petrol used in the cars which had been tampered with in order to cause such an explosion. As a result most form of transportation from cars to aeroplanes are reducing their fuel usage, thus affecting the economy.Additionally political pressures are intensifying, placing the world on the brink of war, and Captain Haddock is mobilised in expectance of such an outbreak of hostilities. After following different leads, Tintin and Thomson and Thompson set off for Khemed on board a petrol tanker. Upon their arrival, the three are framed and arrested by local police. The Thompsons are found with heroin in their cabin while Tintin was found in possession of serious documents concerning the rebel leader, Sheik Bab El Ehr. The Thompsons are cleared and freed, but Tintin is abducted by Arab guerrillas. In the original version of the story he initially arrived in the port of Haifa in British Palestine and was first captured by members of the Irgun, before being abducted by Arabs subsequently.During these experiences, Tintin re-encounters his old enemy, Dr. J.W. Müller from The Black Island, whom he discovers is responsible for sabotaging the oil pipelines. He reunites with the Thompsons and finally arrives in Wadesdah, the capital city of Khemed, where he comes across his old friend, the Portuguese merchant Senhor Oliveira de Figueira. When the Emir of Khemed Mohammed ben Kalish Ezab's young son, the Crown Prince Abdullah, is kidnapped, Tintin suspects that Müller, working under the name of “Professor Smith,” is responsible. He chases Müller with hopes of saving the prince. In the process he discovers Müller to be an agent of a foreign power, and that he is indeed responsible for the tampering of the fuel supplies.Doctor Müller had devised a unique type of chemical in a tablet form that intensifies the explosion power of crude oil by a considerably. The Thompsons find some of the tablets and swallow them, thinking them to be aspirin. This causes them to continuously burp, hiccup and grow long hair and beards that constantly change colour. After studying the tablets, Professor Calculus comes up with remedies for the Thompsons as well as a countering agent to the affected oil supplies, though, in the process of carrying out these tests, he half-destroys Captain Haddock's estate; Marlinspike Hall, earning his understandable ingratitude.