In Act One of the intricate story, the hero Sang Thong is supernaturally born in a conch shell. He is, in fact, a god incarnated in a conch shell in the womb of a childless queen. The queen’s strange childbirth is the subject of much attention at court, and an evil concubine plots with the court astrologer to eliminate the queen. Reluctantly, the king banishes his consort to a forest, where the saddened queen cherishes her conch shell in the hut of a poor couple. One day, the spirit of the forest decides to help the queen by enticing Sang Thong out of his shell. There is no limit to the queen’s surprise when she discovers a beautiful little boy on the steps of the hut, whom she recognizes as her own son.
In Act Two, the evil concubine hears of Sang Thong, and drugs the king with aphrodisiacs so that he orders the boy to be killed. The king recovers too late from the spell; to his horror he discovers that his son has already been drowned.
In Act Three, Sang Thong, who had been cast in the water, finds his way into a kingdom of monsters, where he is looked after by a childless demon-queen, who in human form loves Sang Thong like her own child. But she cannot give up her monster’s habits, and regularly visits the world of humans to catch people for her food. Sang Thong spends fifteen years among the demons, until one day, when his foster-mother is out hunting for human flesh, he becomes curious and enters the forbidden rooms of the palace, despite her express orders. To his horror, in these rooms he finds the bones and remains of human bodies, which reveal his foster-mother’s true nature. He goes on to find a golden well where the water turns his finger into gold. He also finds a black man’s disguise, and a magic wand and shoes of crystal that enable him to fly.
In Act Four, Sang Thong flees the palace, but the demon-queen, yearning for her son, looks everywhere for him. Finally, the heartbroken foster-mother dies of her own sorrow, but not before blessing her son with a secret charm.
In Act Five, the ageing king of Samon faces a problem. He must find suitable husbands for his seven daughters, and decides to arrange an audience for all the eligible men in his kingdom. To her father’s dismay, the youngest princess, Rochana, does not wish to choose any of the candidates.
In Act Six, the perplexed king asks if there is an eligible man left in the kingdom, and he hears of a strange black man living in the forest. Reluctantly, the king has the man, Sang Thong in disguise, brought to court. To her parents’ horror, Rochana gives her consent by throwing a white garland onto Sang Thong’s crystal wand. The young couple is banished to a forest hut, where Sang Thong reveals himself as a divine prince to his bride, and they become husband and wife.
In Act Seven, the king plans a way to get rid of the black man, and arranges a fishing competition for his sons-in-law. The one who cannot bring back a hundred fish to the palace must forfeit his life. The confident husbands of the six daughters set out with their servants. Sang Thong, now in his divine form, uses magic to put a spell on the fish, promising to break the spell only if the men cut off the tips of their noses. Horrified, the men agree to this and downheartedly return to the palace with their fish. The princesses faint when they see the shame brought upon their husbands. After a short while, to everyone’s dismay, Sang Thong, again disguised as the black man, comes to the palace with a large catch of fish.
In Act Eight, the god Indra, high in the heavens, discovers the humiliation of Sang Thong and Rochana. Indra sends a heavenly messenger to challenge the men of the court of Samon to a polo match. If the court players lose the match, the kingdom will be destroyed. The six fear-stricken sons-in-law lose the match, and only when Sang Thong is brought into the game is victory assured. When they see Sang Thong in the form of a handsome prince, the king and queen of Samon regret their former acts.
In Act Nine, Indra comes down to earth to Sang Thong’s father and urges him to find the banished queen. The king finds his wife in a hut in the forest, and she forgives him for all the wrongs he has done. In the guise of commoners, they wander into the kingdom of Samon, where they serve at the royal court. The queen uses secret messages to reveal her true identity to Sang Thong. Their reunion is a joyous one, bygones are forgiven, and Rochana, Sang Thong, and his parents leave for their own kingdom.