Pure gold, Hollywood biography the way it should be told--and may other celebrity biographers take it for a model. Davidson--once he has sketched in Tracy's youth in Milwaukee, early marriage, and young manhood on the road--tells great swatches of the actor's stow from the mouths of eyewitnesses, a tape-recording technique that builds and deepens cracklingly without the muffling effect of rewriting interviews into the third person. Davidson must have an elephant's memory. His own interviews with Tracy go back many decades, as do his tapes of Tracy's coworkers (Sid Caesar, Elizabeth Taylor, Gene Kelly, Pat O'Brien, Richard Widmark, Ernest Borgnine, Robert Wagner, Elia Kazan, etc.) that Davidson has gathered in the course of writing nine previous celebrity bios. Tracy's alcoholism has long been known, but Davidson works up a year-by-year account of Tracy's battle with his demon. He also clearly agrees with recovering alcoholic Dana Andrews' view that a drinking actor should not have his dumb fights and broken furniture and police bookings hidden from the press by studio publicity managers. The alcoholic should be allowed to hit bottom, where he might perhaps wake up to the consequences of his illness and seek help. Despite booze, Tracy was a quick study with a phenomenal memory and learned his craft easily. He liked to attribute his uncanny stage presence to working with George M. Cohan, but fellow Milwaukeean Pat O'Brien tells that Tracy's underplaying was already in place before he left Milwaukee. His marriage foundered on his philandering and famed disappearances (he would rent a hotel room, stock the bathroom with whiskey and live in the bathtub for a week). At first, his Catholicism and family commitment (his son was born deaf) prevented a marriage to Katharine Hepburn; later, he said that Kate wouldn't marry him. He remained almost crippingly insecure about his talent to his dying day. Digs in, especially about craft in the later pages. And don't be surprised by a few tears blurring the page.