Mrs. Anna Leonowens and her son Louis arrive in Bangkok, where she has been contracted to teach English to the children of the royal household. She threatens to leave when the house she had been promised is not available, but falls in love with the children. A new slave, a gift of a vassal king, translates "Uncle Tom's Cabin" into a Siamese ballet. After expressing her unhappiness at being with the King, the slave decides to make an attempt to escape with her lover. Anna and the King start to fall in love, but her headstrong upbringing inhibits her from joining his harem. She is just about to leave Siam but something important she finds out makes her think about changing her mind.

On a scientific expedition to Siam young Billy Batson is given the ability to change himself into the super-powered Captain Marvel by the wizard Shazam, who tells him his powers will last only as long as the Golden Scorpion idol is threatened. Finding the idol, the scientists realize it could be the most powerful weapon in the world and remove the lenses that energize it, distributing them among themselves so that no one would be able to use the idol by himself. Back in the US, Billy Batson, as Captain Marvel, wages a battle against an evil, hooded figure, the Scorpion, who hopes to accumulate all five lenses, thereby gaining control of the super-powerful weapon.

This is the story of Anna Leonowens, the English schoolteacher who came to Siam in the 1860s to teach the children of King Mongkut. She becomes involved in his affairs, from the tragic plight of a young concubine to trying to forge an alliance with Britain to a war with Burma that is orchestrated by Britain. In the meantime, a subtle romance develops between them.

In 1862, a young Englishwoman becomes royal tutor in Siam and befriends the King.