Story spoiler:
Tintin is on a cruise bound for the Far East. He meets on board an eccentric Egyptologist named Sophocles Sarcophagus in search of Kih-Oskh's tomb. Tintin agrees to join him. Tintin discovers in the tomb some mysterious cigars and is kidnapped. Left alone to drift at sea, he's nevertheless saved and lands safely in Arabia. From there, after many an adventure, he ends up in India in the house of Maharajah Rawajputalah. He then takes it on himself to fight the opium trade and manages to dismantel Rastatopoulos gang. By the end he discovers that the cigars were filled with the opium he was after.