Plot
In 1862, Anna Leonowens and her son Louis sail from London to Bangkok, where Anna is to serve as teacher for the children of King Mongkut. Kralahome, the Prime Minister plotting to usurp the throne, attempts to prevent her arrival by using his powers of illusion to make it appear the ship is being attacked by a giant sea serpent; however, Anna, Louis and the crew manage to fend off the apparition by whistling a happy tune.
Arriving in Siam, despite being promised her own house outside the palace, Anna finds she has been denied it. Hoping to use Anna to achieve his goal, Karalhome informs her the King regularly goes back on his promises while exaggerating every one of the King's flaws. Since she will not receive the house, Anna decides to leave, but she changes her mind after meeting the royal children and seeing another side of the King after visiting his workshop, where he makes miniature trains and hot air balloons.
In the Grand Palace, Anna witnesses Mongkuk receive a young woman named Tuptim from Burma as a gift. While serving in the palace gardens, Tuptim meets Prince Chulalongkorn and the two begin to develop feelings for each other, but Chulalongkorn keeps his true identity hidden. Anna sees Chulalongkorn and Tuptim meeting in the garden and supports their relationship. Despite her reservations about the king, Anna begins teaching the royal children; learning they have never been outside the palace walls, she takes all of them around the city to see how other people live. Informed of this by his henchman, Master Little, Kralahome informs Mongkut of the outing; Mongkut subsequently confronts Anna, who angrily refutes his authority.
With Kralahome still plotting to overthrow the King, he writes a letter to officials from the British Empire, warning that Anna is in danger. Chulalongkorn discusses traditions with his father, informing him that he does not want to have multiple wives like him. Tuptim finally learns that Chulalongkorn is the crown prince and that their love is forbidden; however, he tells her that he does not care about tradition and wants to be with her. Master Little learns of their relationship and tells Kralahome, who plans to use it to anger Mongkut.
The King is troubled after learning that the British are coming because he is allegedly a barbarian. Anna advises Mongkut to throw a banquet for the British when they arrive to show that he is civilized. At the dinner, Kralahome reveals Chulalongkorn and Tuptim's relationship by showing Tuptim is wearing Chulalongkorn's royal ivory pendant. Dishonored, the King threatens to whip Tuptim to death but instead orders her to be sent back to Burma. Knowing that this will mean death for her, Chulalongkorn turns against his father and flees with Tuptim into the jungle.
As Chulalongkorn and Tuptim escape, Kralahome uses his powers to put the two in constant danger, leading to them to being caught in a river's current at the border of the Kingdom. The King uses his hot air balloon to rescue them, but in the attempt Kralahome destroys the balloon with a firework, and everyone but Mongkut safely jumps into a lake. Kralahome celebrates his apparent victory in the murder of the king but instead exposes his true nature in front of the British and the royal guards. Mongkut survives the crash and tells his son to be ready to lead Siam if he dies, allowing him and Tuptim to marry. With his scheme exposed, Kralahome and Master Little are forced the clean the elephant stables. The King heals from his injury and presents Anna with her house outside the palace walls.
