"The Enchantress" by Han Suyin -- call it a high-class romance fairy tale, or a historical fantasy, or a romantic-historical fairy tale.

But where does one go from there? How does one equate this silly little story with the Suyin of the "many splendored" love affair that became a best-selling novel and a hit movie? She has written more than 15 books, most of them based on her life as a Eurasian child growing up in China, her experiences as a young western-educated medical doctor observing the Communist revolution from the Hong Kong border and then returning to the mainland to live, work and write about the aspirations of its people, their high ideals and hopes, along with the pain, the excesses and horrors of the Cultural Revolution.

Granted, the historical details of "The Enchantress" have been meticulously researched. But it is all for naught, because the plot upon which the whole exotic panorama hinges is almost laughable in its attempt to touch upon every facet of the 18th century, while the characters are no more human than the automata-robots that were the rage of the rich and royal of the day.

Golden Ayuthia, City of Paradise -- the ancient capital of Thailand -- is "The Enchantress." To it, in a very roundabout way, come Bea and Colin, Swiss twins who become embroiled in its political and palace intrigues and are caught in the whirlwind when Ayuthia is destroyed by invading Burmese armies.

They are the children of a beautiful Celtic mother who practiced the ancient magic of her people and a freethinking baron, who are killed by village neighbors turned into a witch-hunting mob. Colin has inherited his father's mechanical talents, while Bea has her mother's supernatural powers. They share a symbiotic relationship, often speaking silently to each other -- even over great distances, and especially at times of danger.

Mistreated by their paternal uncle, the orphans and Valentin, their half-brother, escape from the family estate and find their way to Geneva. There, Abraham Hirsch, their father's Jewish banker friend, arranges a mercenary posting for Valentin, and for the twins to hitch on with an exotic business venture of a noble Moor named Abdul Reza. By astonishing coincidence, his plans involve the building and repairing of automata and clocks at the Chinese Imperial Court.

Subsequently forced to flee China because of palace politics, Colin and Bea journey to Ayuthia. On the same day that Colin falls in love with a gentle beauty who resembles his mother, he makes the deadly mistake of winning a boxing match against a prince with high connections. Strong-willed, seductive Bea, with the sparkling green eyes and scheming mind, marries a good-natured nobleman she doesn't love and then falls for an austere conquering hero.

Suyin's writing is often excessively sentimental. What has always saved her books is the detail, the depth of her characters, her ability to create persuasive plots and her and sensitivity toward the world and people she is writing about.

"The Enchantress" touches on many interesting subjects, especially the 18th-century fascination with all things mechanical, and deals with other topics: the worldwide impact of the Jesuits; the perilous condition of Jews in Europe; trade and cultural exchange between the Occident and the Orient; Asian palace life, including the many esoteric methods of torture and execution. And finally Suyin tells the story of how Ayuthia, of the 300 golden spires, fell because the king, so sure of his heavenly omnipotence, refused to allow any defense against the invading Burmese.

But all of this teeming, colorful activity serves merely as a shallow, painted backdrop to Bea and Colin's Happily Ever After odyssey. Shades of Voltaire! -- who, by the way, is also a part of the action. It's as if the story of Candide and his sister Cunegonde had been rewritten for the modern Harlequin romance market.