Molly Moon's Incredible Book Of Hypnotism by Georgia Byng Macmillan $170 PUBLISHERS HAVE finally woken up to the fact that writers of children's books can be huge money-spinners on the open market. J K Rowling with Harry Potter and Philip Pullman (who made the long list for the Booker Prize) in particular have opened up revenue avenues previously confined to best-selling adult material. Publicists are trying to catapult Lady Georgia Byng into the same category with Molly Moon's Incredible Book Of Hypnotism. British producer David Heyman has bought the film rights, and the book - aimed at children aged eight and above - is creating enormous interest. But, frankly, it is difficult to see what all the fuss is about. Byng, the 36-year-old elder daughter of the Earl of Strafford and stepdaughter of Sir Christopher Bland, former BBC chairman, has taken an original and compelling idea and has produced an entertaining read. But the book lacks depth and consistency. While Molly, the heroine, seems to have little difficulty justifying stealing a rare and valuable book revealing the secrets of hypnotism from her local library, she struggles with the dilemma of using her new-found powers to become rich and famous through trickery and skulduggery. An orphan, Molly is uncoordinated and accident-prone. Her dreams of popularity appear to come true. However, as the story unravels so do her illusions. She comes to realise that rejection can be dealt with in more realistic ways and in the end it is friends and people that matter above all. In her miserable orphanage she had been led to believe she was rotten at everything, but Molly learns she has the power to learn and to enjoy life on her own terms. Talk of children using the book to meddle in the dangerous arts is overblown. As the book aptly puts it: '. . . adults underestimate the intelligence of children'. While some of the material enables a little harmless experimentation, the chances of youngsters hypnotising virtually everyone they meet are about as likely as this book winning the Booker Prize. Byng has written a pleasing fantasy that draws readers along effortlessly. As the action veers between Britain and New York, characters as diverse as a phoney professor with a sad past, criminal plans and a sadistic streak, a hard-nosed theatrical agent and a spoiled-brat starlet engage in a series of sub-plots that seamlessly weld together to form a cohesive whole. Amusing and, at times, tense, the suspense builds to a conclusion which is neat, although not surprising. The best children's literature has more challenging features. Yes, there is drama and insight in a plot spiced up with moral ambiguity and thoughtful reflection. But while this tasty morsel is a recipe for limited success, it is not the satisfying dish the world of children's books has been hungering for.