An intensely dramatic, well-constructed, but unfortunately overwritten debut--about an androgynous teenager's powerful effects on those who fall under his spell--by a Lebanese-Irish American heretofore known for his poetry. If ""the boy"" is this novel's protagonist, both his and the novel's antagonist is Scan Hennessy, a former social worker bereft of his beloved ex-wife and two children, both dead, who searches the London streets for Pierce, his foster-son--and, Scan believes, owing to an ill-advised liaison with an unstable client, his natural child as well. A series of parallel narratives details both Sean's progress (and also the mixed motives that propel it) and the changes that were wrought by the boy Pierce (or Durward, or any of the several other names he assumes) in Sean's clinically depressed daughter Megan (whose diary is excerpted) and in his critically ill son Liam; the life of Theresa, matron of a Home for Boys where ""Devon"" briefly lived; and the doings of ""the fat man,"" the weak-willed ""Daddy"" who adores ""Alex"" (another of the boy's incarnations), the angelic ""rent boy"" for whom the fat man will commit any act--including murder. Murr juggles these separate stories adroitly, and keeps us guessing about the good-vs.-evil duality that motivates the boy's actions. But his story is crucially flawed by its reliance on a hoary cliche: The boy's passionate sense of life seems preferable to his acquaintances' inability to commit themselves fully--either to people or to ways of living. (Both James Purdy's novel Malcolm and Pasolini's film Teorema may have influenced Murr.) And there's a tendency for these characters to overexplain themselves, speaking and thinking in unconvincingly abstract terms (as when the boy speaks of his influence over the trusting Megan: ""She had such a meager soul, but with the husbandry I've learned of necessity, I made quite a feast of it""). Technically a capable debut, though the unreality both of its Mephistophelean central figure and of his beneficiaries and victims makes it, finally, unconvincing.