Ah, Hollywood, land of dreams, epicenter of illusion, where nothing is ever as it seems, where anything goes as long as it sells popcorn, where even Mob hit men conceive sentimental yearnings to produce motion pictures. Such, at least, is the world that John Gregory Dunne conjures up in his witty, highly entertaining novel Playland. This is the improbable tale of child actress ''Baby Blue Tyler, Hollywood's number-one cinemoppet,'' who sank without a trace one day in the early '50s, and was rumored to be dead in Walter Scott's Personality Parade, only to make a reluctant reappearance more than 40 years later in a Detroit trailer park.
But how to penetrate to the truth of Blue's mysterious disappearance? That's the question that preoccupies screenwriter Jack Broderick, who happens upon the onetime child star by accident while in Detroit researching Murder One, a script about a short, white homicide detective and his sidekick, a 7', black retired basketball player. While eager to tell some parts of her story, Baby Blue turns out to be what's called an ''unreliable narrator.'' That's partly because she's still reluctant to discuss her doomed love affair with slain gangster Jacob King (real name, Yakov Kinovsky), who was known publicly as a ''Millionaire Sportsman'' and behind his back as ''The Great Gatzberg.''
But there's more to it than that, a great deal more, Broderick discovers as he begins to piece together something resembling the truth from a variety of equally shaky sources: old letters, yellowing newspaper clippings, fan-mag pieces cooked up by studio shills, witness statements, grand jury transcripts, aged newsreel footage, columns by Walter Winchell, Louella Parsons, and Hedda Hopper. Even the eyewitness accounts of Broderick's two old friends, director Chuckie O'Hara and Arthur French, the son of Cosmopolitan Pictures mogul J.F. French (real name, Moses Frankel), can't be relied upon for accuracy.
''Did it really matter if what happened did not actually happen that way?'' Broderick is tempted to wonder. ''We were just advancing the action. Story-conferencing the truth.... Facts are unforgiving, so f--- facts, make the scenes work.'' Dunne, the author of True Confessions and several screenplays for Hollywood, knows his territory inside out. If marred a bit by a sexual explicitness that occasionally partakes of the crassness it means to satirize, Dunne's Playland gives us an acerbic portrait of a world in which both for better and worse almost everybody's an impostor. A-