THERE ARE some writers who seem determined to ignore the possibility that their readers may be possessed of any native intelligence. Victoria Holt (a.k.a. Jean Plaidy and Philippa Carr) has built a successful career by writing historical novels whose plots are convoluted and contrived, whose characters are unlike any real human beings and whose language seems deliberately intended to provide no challenge to anyone with more than a first- grade education. Her latest book, The Demon Lover, is no exception.

An exciting plot, stirring times, characters of illustrious ancestry, dark castles and fiery women have been the stuff of many entertaining novels, but Holt prefers the trite, the hackneyed and the careless phrase to any fresh approach. Her Victorian heroine, beautiful Kate Collison (with a nod to current susceptibilities, Kate is interested in a career) is a painter of miniatures, who accompanies her father to France to paint the notorious Baron de Centeville in his genuine Norman castle. The baron is the typical hero of the genre, ruthless, savage, with piercing eyes, but turned into a pussycat by the love of a good woman, whose fate it is to be overwhelmed, almost ruined, before granting forgiveness.

Kate remains in France, earning her living as an artist in Paris, where her reputation has been established by her portrait of the baron. She rears her illegitimate son in the home of the baron's discarded mistress, Nicole. But as this is an historical novel, some of the outside world must be included. France under Napoleon III goes to war with Prussia, Paris is besieged and Kate and the baron predictably meet again. The historical background is irrelevant for these stereotypes conduct their lives in timeless caricatures of reality. The plot is twisted and turned like a rubber corkscrew but the result is a vin ordinaire of the most mediocre kind rather than a vintage of some presumption.