Already a film, and probably originally conceived as such, this tale of a Scottish police officer lured to an isolated private isle will be familiar, in outline at least, to fans of horror/voodoo cinematics. Virginal, stoically proper, birdwatching Sergeant Neal Howie flies his sea-copter to Summerisle when word comes to the mainland that twelve-year-old Rowan Morrison has been missing for a year or so. But no one on this strangely warm island will admit that Rowan ever existed--not even her supposed mother and sister (though Sis claims to have a rabbit named Rowan). Stranger still, the island seems to be a primitive ""totally alien society,"" with anti-Christian teaching at school, Hieronymus Bosch-y mass couplings on the village green, not to mention the unlikely flora and fauna. And what about that doctor's bag full of vipers or that mother pushing a frog into that little girl's mouth or that openly salacious wench at the inn who Sgt. Howie fears is after his ""precious seed""? Is Rowan Morrison already dead--or being prepared for a May Day fertility ritual? Or--since Sgt. Howie's copter is mysteriously out of commission--could someone else be the virgin sacrifice that the islanders have in mind? Neither the movie-minded accelerating-terror formula nor the special effects (a real grisly finale) translate especially well into prose, but there's more literacy afoot here than we've any right to expect, and readers with a pagan predilection might as well get it in this relatively classy package.