Derek Marlowe is an elegant entertainer and his stories, from Dandy in Aspic to the Californis-styled thriller, Somebody's Sister, are full of startling conjecture. Now Amy and Edward Lytton, quiet English sorts, ""the best of friends"" and the most inviolate of couples, come to Haiti where Edward loses touch with Amy, who's more impressionable and daydreamy from day to day, given to ""little games"" (she appears one night looking almost like a whore), off alone who knows where, and having strange lapses and transpositions. Sometimes Edward is reminded, reluctantly, of her sister Blanche who died there some years ago; in Haiti deaths unattended by the last rites are not final at all--there are those revenants, hostages to the God of Death, Baron Samedi. Amy does the most unexpected things--slipping into French (a language she never learned), misplacing her hat, or is it herself? Marlowe, a mandarin writer, tells his story in suggestive stops and starts with broken innuendos and suggestive shifts. One is trapped on these empty beaches or in the old hotel where lizards crawl on balconies and rats scuffle behind louvered windows. A seductive horror story--how easily one gets lost after dark--behind the pages of a book like this.