Though slightly less admiring and somewhat franker than Mel Gussow's Don't Say Yes Until I Finish Talking (1971), this new biography of mogul Darryl F. Zanuck doesn't add significantly to the record--aside from the update covering DFZ's miserable last few years, On the personal side, Mosley wonders why crude/macho Zanuck ""treated women like sex machines""--and explains it by emphasizing DFZ's virtual abandonment by his lustful mother. (""He would never trust a woman again."") Hence his extramarital affairs with such as Dolores Costello (""one thing led to another"") and Ann Harding (""one thing led to another""), his one-starlet-a-day office sex. The professional career is filled in with a bit more finesse--from the writing dreams of Midwestern boyhood to pulp-stories, gags, and scenarios in post-WW I Hollywood; from Rin-Tin-Tin screenplays for Warner Bros. to whiz-kid head of production during its heyday; from Twentieth Century (his own company, with Schenck and Goetz) to the merged 20th Century-Fox. Mosley calls Zanuek, who loved writers (especially Nunnally Johnson) but hated directors, a ""born storyteller."" He gives DFZ credit for tackling controversial themes, for keeping his trash-films fast and actire, for inspired ""rejigging"" and editing. (Factual errors here and there don't give one total confidence in Mosley's information about who-did-what-when during the writing/filming/editing process.) And, after the DFZ-career peak, circa 1950, the narrative concentrates on: his youth-seeking affairs with sex-bomb Bella Darvi (whose lesbianism finally turned him off) and liberated-woman Juliette Greco; his resiguation from Fox, his independent foreign productions; his comeback via The Longest Day; and, with quotes from son Richard, the final years of Oedipal feuding and illness. Uninspired, serviceable tinsel-town fare from a veteran biographer--with enough raunchy anecdotes and film-by-film data to satisfy some movie buffs.