One fine sunny morning, the Thompsons have taken their car for a drive. They stop to refill at a petrol pump and get a drop of petrol in their pocket cigarette lighter too. They drive away, chanting happily to a tune, when suddenly, the car's engine bursts with a loud bang. Apparently it seems to be a fault with the car. The Thompsons dial Autocart to repair their car and settle for a smoke. As they try to light their cigarettes, the lighter too bursts. It becomes evident that there is something wrong with the petrol.
The next day, Tintin reads the news papers about the petrol disasters. He fears a war will take place, if the malady goes unchecked. Suddenly, Haddock rings up and says that he is leaving on an assignment. The Thompsons come in and discuss about the matter with Tintin. They put the blame on Autocart, saying that it being a vehicle repair company, might be adulterating the petrol for their own profits. They plan to work for Autocart and gain information from inside.
Next day, the Thompsons apply as drivers and take jobs inside Autocart. The first day, they mess up and bungle their ride. The next day, they get inattentive while pressurizing a tyre and burst it. Immediately, they are thrown out of the company.
Menawhile, tintin tries to get information about petrol sales. He sees that petrol sales have reduced drastically. The laboratories try in vain to decipher the harmful contents of the petrol. That night, Tintin hears some suspicious conversations at the shipyard. He almost blows his cover with a loud sneeze, but Snowy proves to be a distraction to the thugs. They depart. Tintin plans to join the "Speedol Star" as a radio operator.
The Thompsons too are assigned duties on the same ship. They board the ship as cabin crew and get punished for behaving rudely with the captain.
That morning, while walking down the ship's corridor, a thug from the previous night spots Snowy and immediately gets suspicious. He tries to get rid of Snowy, but gets bit himself, and runs.
That night, Tintin returns from delivering a message to the captain and immediately smells trouble. He sees that Snowy has been chloroformed and taken away. He gets into a brawl with a marine after hitting him out of suspicion. The marine slams him into a cabin. The thug is there, trying to drown Snowy. He too gets hit by the marine and falls down. Tintin opens the bag and reveals a drugged Snowy. He demands answers from the thug but recieves nothing useful, for the thug has become mad after he hit his head.
Next morning, a water patrol comes onboard the ship. They claim to have come for a routine checking. They reveal unlawful documents about Babel Ehr from Tintin and the Thompsons' cabins and take them into custody.
Some distance away, Babel Ehr's spies see Tintin being taken away, and plan to free him. Next morning, they accomplish their task with a gas bomb. They stun the police and take Tintin away.
Meanwhile, the Thompsons are released from the police headquarters. They are asked to bring Babel Ehr to custody and will be offered a monetary prize for that. They depart immediately.
Meanwhile, Tintin is taken to Babel Ehr. Babel welcomes him with open arms and asks about the weapons. Tintin is taken aback but recalls the papers in his cabin. Babel thinks him to be aspy and detains him. Suddenly, a plane flies overhead. Babel recognizes it as the Aamir's plane. The plane releases papers into the air. A bunch falls on Babel's head and he slanders the Aamir. He prepares the party for departure.
Meanwhile the Thompsons drive in the desert and see mirages. They think a palm tree to be a mirage and crash into it. Next morning, they repair their jeep and depart again. They mistake a mirage for a real pool and jump into the hot sand. Later, they mistake a real oasis for a mirage and drive into the water.
Tintin walks along with Balbel Ehr's party. His throat is parched. He falls down faint. They release him and go away. Later, Snowy wakes Tintin up and they set off for a destination. They come across a stretch of water and drink to their heart's content. Night falls. Tintin retrieves some dates(a kind of fruit) from a tree and they eat together. They try to sleep but are woken up by a sudden noise. Tintin sees horsemen dismounting and fiddling with the gas pipelines. Suddenly they run away and the pipelines burst behind them, spewing flames and smoke into the night.
After that, all but one depart. Tintin seizes this chance to overpower the remaining man and get involved in the matter. The head divides the group and takes Tintin with him. He dismounts from his horse near some rocks and Tintin cannot hide his curiosity to go after him. Tintin sees that the man is his past foe, Doctor Muller. Suddenly, Dr. Muller disappears around the corner and catches Tintin and Snowy off-guard from behind. He plans to get some answers out of tintin. But suddenly, he hears the sound of a jeep. He goes to hide the horses and comes back to see Tintin awake. He shoots his way out and takes away both the horses. Tintin starts following the horses' footsteps.
Nearby, the Thompsons lose their way and start boing in circles. But still, they cannot understand their flaw. They find their can of petrol but cannot recognize it.
Suddenly a dust storm rises. Tintin and Snowy get trapped. HE hears the sound of a jeep and tries to attract attention. It is the Thompsons but they are too busy to hear extraneous sounds. Tintin fires two shots and manages to attract their attention. Afterwards when the storm subsides, Tintin falls asleep and seeing him, the Thompsons too fall asleep at the wheel. The jeep drives itself into a nearby town. A confusion ensues and the Thompsons are arrested for rash driving.
Next morning, Tintin goes to see the Aamir, Mohammed Ben Kalish Ezab. He overhears a quarrel going on and just manages to hide himself and Snowy from view when he sees Dr. Muller stepping out. The servant comes and takes him to the Aamir. Tintin requests the Aamirto withdraw the Thompsons' punishment. When the Aamir asks what they were doing out in the desert, Tintin starts relating his story. Two hours later, as he draws a conclusion, Ezab tells that a foreign oil company is trying to oust the local company from its position. Dr. Smith is talking on the behalf of the foreign company. Tintin understands that Dr. Smith is Dr. Muller. He continues with his story.
Suddenly a servant informs Ezab that his son, the prince, Abdullah is missing. At first Ezab doesn't believe him, but he gets solid proof later when aletter comes telling him to drive away the local oil company from Khemed. It bears Babel Ehr's signature. Ezab gets mad with anger.
Later, Ezab deploys 300 horsemen in search of Abdullah. Tintin plans to go to Wadesdah, because he believes that Abdullah may be present there.
Next morning, Tintin goes to Wadesdah and meets his old friend, Senor Oliveira De Figuera. He discusses his plans with him to gain entry into Prof. Smith's house.
Next morning, the two of them go to Smith's house. Oliveira cleverly diverts the servants towards him while Tintin slips away from the scene. He sees an open window on the first floor and latches a rope from it, then climbs up. He see the room to be empty.
Suddenly, the fireplace opens and Dr. Muller pops up, sneezing. He keeps a box of sneezing powder on his table. But a wasp disturbs him and in an effort to squash it, he wipes off the entire table top. The sneezing powder spreads out into the room. He goes out sneezing and is alerted to Tintin's presence. Then there's some serious action. Both of them try to overcome each other. In the end, Tintin tricks Muller into hurting himself and binds him securely.
Tintin arms himself and goes down the fireplace. He comes into a bunker with rail tracks all around. He disarms a sentry and forces him to free Abdullah. But Abdullah's pesky nature earns Tintin a huge loss. tintin manages to overpower the sentry but he later gets away.
The sentry frees Muller and they begin searching the underground track system with guns, from both sides.
Abdullah proves to be a very disobedient boy. His mischief costs Tintin his cover. The thugs catch Abdullah and fire at Tintin. Tintin gets himself into a room full of crackers but a stray bullet from the thug sets fire to them. The whole room fills with bursting explosives.
Suddenly, Tintin hears shots outside. He opens the door and is greeted by Haddock and Snowy. Tintin asks about Abdullah but Haddock hasn't seen him. They come up and get news from the Aamir that Muller has kidnapped Abdullah and driven away in a car. Tintin and Haddock give chase in the Aamir's car. They pass the horsemen and the Thompsons.
Abdullah's peskiness causes Muller to lose control of his car and it overturns. Tintin and Haddock come up, but Muller brings out a gun and threatens to kill Abdullah. Abdullah gives him a second gun. Muller shoves Abdullah into the Aamir's car and takes off. But Abdullah jumps out. Tintin blows out the car's tyres and Muller runs away.
Tintin blocks Muller from firing Haddock. As Muller goes out of ammunition, he tries to commit suicide. But Abdullah's pistol is really a fake ink squirting pistol.
The Thompsons find a tube of aspirins and take one each. but immediately, they fall sick. Tintin plans to take them and Muller in his jeep. Muller tries to coax him into destroying the aspirins, but Tintin refuses. Later, after Muller has been reprimanded, he takes the Thompsons to a hospital. By that time, they are covered in hair.
Later, Abdullah is returned to his father. Tintin reveals Muller's name to Ezab and briefs him of Muller's espionage activities.
A few days later, Calculus sends a letter. He has successfully deciphered the aspirins to be powerful explosives. He has also sent medications for the Thompsons. The story ends, with Haddock very displeased with Abdullah's cheap tricks.