Tintin and his dog Snowy are on a cruise ship in the Mediterranean Sea when they meet Dr Sarcophagus, an Egyptologist who owns a papyrus that he believes will lead him to the undiscovered tomb of the Pharaoh Kih-Oskh (a pun on kiosk, a newspaper stand). He invites Tintin to accompany him. Tintin also has an unpleasant encounter with Roberto Rastapopoulos, a wealthy businessman.
Later on the cruise, Tintin first meets the Thompson twins, who accuse him of smuggling opium they have found in his cabin. Locked in the hold of the ship, Tintin craftily escapes and meets Sarcophagus in Port Said, Egypt.
Tintin and Sarcophagus set off and discover the tomb of Kih-Oskh. On a nearby sand dune, Tintin finds a cigar bearing the symbol of Kih-Oskh — a circle with a wavy line through it and two dots on it, rather like a yin-yang symbol. But when he returns to the tomb, Sarcophagus has disappeared. Tintin calls out his name, but to his surprise, finds a door leading into the tomb. Tintin steps inside and the door locks behind him.
Inside the tomb, Tintin is in for a nasty surprise, when he finds out the mummies of earlier explorers inside coffins, and also three coffins reserved for him, Snowy and Dr. Sarchophagus. Tintin collects some suspicious cigars, but faints when a strong drug is released into the room.
Later, some men carry the three new coffins to Alan the smuggler's ship. When Alan sees coastguards, he drops the coffins into the sea. Later, when he recieves a message to guard the coffins, he orders a fresh search.
By morning, Tintin breaks himself and Snowy out of the coffins. He finds Dr. Sarcophagus floating some distance away, but the steady currnts separate them. Eventually, Sarcophagus is found by Alan.
Tintin and Snowy caught in a stormy sea. A huge wave hits them. Later, Tintin finds himself on a ship. He meets Senor Alviera. Later, he meets Rastapopulous inside a desert film shooting. Coming back to the ship, he discovers heavy weaponry stowed away. He is caught by the captain, and later by the Thomsons. When Snowy drops a grenade, they flee and Tintin escapes.
Walking through the desert, Tintin is attacked. Later, he finds the Thompsons again and escapes them. He walks into a city and is unwillingly recruited into the army. He discovers the same suspicious cigars. The colonel sentences him to death.
But the Thompsons hatch a plan and save him. The guards attack them and the flee. Tintin finds an aircraft and takes to the skies. Out of fuel, he lands in an Indian jungle. He runs into Sarcophagus again. But Sarcophagus is mad. So Tintin takes him to a villa and request the owner to treat him.
Underneath, plans go on over Tintin's disposal. Tintin is detained in a hospital but he escapes. He escapes the Thompsons once again. He meets the Maharaja of Gaipajama and stays over at his palace. He finds out about a secret gang, but fails to capture a crafty fakir in the group.
The fakir makes off with the Maharaja's son. Tintin pursues him and finds the leader of the organisation. But though he manages to capture the fakir, the leader slips his grip. The prince is rescued.
THe secret of the cigars is revealed. The cigars contain opium to make common people addicts.