"Darling Jim' is the first novel set in Ireland by the Danish-born, Columbia University journalism graduate Christian Moerk. It's spine-chilling stuff, too. When two sisters and their aunt are found dead in their suburban Dublin home, a young postman finds a diary belonging to one of them containing the true life details of the most tragic love story he's ever read. From this point on the author begins to craft a tale of love, jealousy, family feuds, sexual obsession and - this being Ireland, after all - envy. When the dashing young Jim turns up in young women's lives, so does romance and eventually the undertakers. Moerk writes evocatively, if at times a little formulaically about the Irish and their unique peccadilloes. Gifted with a graphic imagination and a prose style to match, you can probably expect to see the film of the book before long. Henry Holt and Company, $25.