A debut mystery, as chock-full of characters as a Russian novel, set in New York's Fire Island, where a string of beach communities caters to the city's singles and upwardly mobile families. Sharon's Landing is a family-oriented enclave, and newly widowed Lily Lambert has returned to her house there, alone for the first time. Days later, in the aftermath of a fierce storm, the body of young tennis and swimming coach Scotty Banks is washed ashore, a bullet in his chest. Lily asks Lieutenant Harry Bell of the Suffolk police, a friend of her brother's, to investigate. Lily knows everyone at Sharon's Landing, and Bell encourages her to help, but not before his sharp questioning has uncovered her romantic involvement with Dr. Will Mortimer, whose wife Caroline is an incipient alcoholic and whose daughter ran away from home after breaking up with Scotty the previous summer. A tangle of thinly sketched residents, uncompelling motives, ferry arrivals and departures, tennis games and parties leads Lily, eventually, to the all-too-hackneyed rash confrontation with a killer and the discovery of a second victim. The plot is overpeopled, choppy and confusing, but the author's Fire Island ambiance is right on target. There's talent here--perhaps better things lie ahead.