Richly researched, smoothly dogged biography of Bette Davis that outweighs in sheer detail Barbara Leaming's strong effort Bette Davis (1991), though in a less lively voice, and that fairly well defines Davis. Spada has written serious bios of Grace Kelly, Marilyn Monroe, Peter Lawford, and many others. Davis's two earliest shaping forces were her attorney father Harlan--a ``cold vacuum'' who thought she had little to offer, which maddened the mercurial Bette--and her mother Ruthie, who quickly divorced Harlan and guided her sometimes raging daughter toward the stage. Though they had wall-shaking rows, Ruthie bathed Bette nightly until well into her teens. Davis worked her way up through regional theaters, being directed by George Cukor in Rochester, early landed Broadway leads and a summons by Warner Brothers. Marriage to early beau Harmon Nelson, an orchestra leader, flopped as her career boomed; ``Ham'' (Harmon) talked her into two abortions. Her fury as the vile Mildred in Of Human Bondage made screen history as she became filmdom's first leading actress ever to set out to be absolutely revolting--audiences cheered when she died. Her first Oscar came a year later for the alcoholic lead in Dangerous, as did her first of many extramarital affairs--with her leading man, Franchot Tone, then engaged to Joan Crawford, with whom Bette feuded right up through their roles as sisters in Whatever Happened to Baby Jane? When Ham records her bedroom noises with Howard Hughes, Spada calls the recording both a disc and a tape--and weakens the reader's faith. The rest of his dirt--more abortions, adultery, alcoholism, rage, husband Gary Merrill strangling her and beating their horse with barbed wire, the split with daughter B.D.--if not fresh, adds pungency. Familiar, and the acting gets slighted, but Davis gives fiery focus.