``We were a ragtag band of inhibited outsiders, each a secret and keeping secrets from the others. And ourselves, I suspect.'' That's how the narrator of this puzzle novel by Tillman (Haunted Houses, 1987; Motion Sickness, 1991) describes the expatriate community that surrounds him on Crete. His name is Horace (or so we're led to believe until we're told in the closing pages, ``Change the name and you are the subject of the story''). He's an elderly homosexual living with a young Greek gigolo, and a writer of crime novels. When Horace develops a strange, largely platonic fixation on a new arrival--a pretty girl named Helen, who, rumor has it, prowled the streets of downtown Manhattan like a black cat and now picks up sailors at the harbor--his penchant for sleuthing comes in handy. The girl disappears, and Horace is compelled to search for her among a band of gypsies in the south of the island. All he turns up is her diary, full of quotes from Patti Smith and odd jottings like ``OEDIPUS WRECKS.'' It disappoints him, but later his old buddy from Harvard, Gwen, enlightens him by explaining that in Helen he was looking for himself. ``How tiresome'' he finds it--that he has never really understood anyone because he can't see outside himself. Unlike Horace's, the author's vision is clear--she's produced a handful of sharply drawn secondary characters and a very interior narrative voice that teasingly commands. But she backs away from sense and message by riddling with matters ontological, resulting in a novel that is by turns frustrating and amusing, if slight. Beach reading for the John Hawkes set.