In his first new work since 1999's Dinner With Friends, Pulitzer Prize winner Donald Margulies has returned to his roots. The title describes the playwright as well as our tortured hero. Eric Weiss (Adam Arkin, making the most of his hangdog eyes), who has penned an is-it-or-isn't-it-autobiographical novel. The book's a best-seller, but his marriage couldn't be worse; Hollywood has come calling, but his ailing father has pushed him away. As wry and comical as Margulies' earlier material (''Imagining Jews as much easier than actually seeing them,'' quips a producer), Brooklyn Boy resonates with something new: unparalleled grace and maturity.