Initially intriguing, often entertaining, ultimately overstuffed: an unsatisfactory but highly promising debut for hip N.Y.C. narrator-hero Artie Deemer--an unemployed jazz musician who makes a very good Upper West Side living as the owner/trainer of Jellyroll, beloved mutt of movie and TV-commercial fame. Artie's convoluted adventure begins with the murder of his ex-girlfriend, down-town photographer Billie--who leaves a posthumous message for Artie in her refrigerator's ice-tray: a strange set of photos, some from Billie's shadowy family-past, some pointing to shady doings at the antique shop across the street from Billie's studio. Soon, then, for the usual (tenuous) reasons, Artie is sleuthing--partnered by another of Billie's many ex-lovers, surly lesbian Sybel, and protected by a dandy Caribbean bodyguard named Calabash. The clues lead to several corpses, to a Staten Island nursing home, to the headquarters of a Mafia-connected tycoon of underground aviation--and, finally, to an midair showdown over the Bahamas. The intertwined revelations involve layers of blackmail, bygone identity-switches, and far-fetched Oedipal motivations. (""This was growing Byzantine,"" says Artie towards the end--and he's not kidding.) But, if the plotting becomes outlandishly gnarled, Artie's zesty narration remains appealing throughout--with fine Manhattan atmosphere, sharp-eared dialogue, and bits of inspired comedy (canine show-biz, Artie's hippie lawyer), And there'll be top-notch mystery-diversion ahead if Murphy can retain his storytelling energy while bringing his stories into sync with Artie's plausible, down-to-earth presence.