Invited to write this ""authorized biography"" by Christie's daughter, Morgan had access to the private Christie papers--letters, manuscripts, diaries, etc.--and to previously un-forthcoming interview subjects. But, while the result is thickly detailed and occasionally intriguing, there's little new light shed on the subjects of greatest interest or importance: the sources of Christie's fearsomely lethal imagination, the reasons for her work's phenomenal success, and the truth about her famous disappearance. In documenting Agatha's Victorian childhood (so gorgeously evoked in AC's Autobiography), Morgan does come up with a few teasing, unexplored clues: her older sister's ""passion for disguise,"" her father's love of amateur theatricals, the feeling that this serene childhood ""was vaguely, but not unmanageably, disturbed beneath"" the surface. When it comes to that 1926 scandale, Morgan reviews all the evidence, considers every theory, and settles on the most commonly held view (nervous breakdown, genuine temporary amnesia)--while railing at the ""greedy, sensational, and importunate"" press. And some of Christie's recurring themes--in the revealing Mary Westmacott novels as well as the mysteries--are remarked upon: maternally possessive love, evil and innocence, mirrors, disguise. Unfortunately, however, though Morgan uses the AC notebooks to provide a glimpse of a Christie plot's development from first notion to finished puzzle, her commentary on the mysteries is painfully thin: there's virtually no attempt at critical assessment; only the most obvious life/work parallels are noticed; faulty generalizations abound (""Her books do not make the blood run quicker""); the few strong insights are duly credited lifts from Robert Barnard's A Talent to Deceive. Nor is there anything surprising in the portrait of Agatha herself: industrious, good-natured, insular (the anti-Semitism), ""self-protective."" And the bulk of this biography, especially in later chapters, is devoted to the minutiae of travel, publishing, playwrighting, and domestic life. In sum: a valuable gathering of facts, documents, and testimony--but too superficial to please serious students of the genre, too lumbering to engage most fans (who'll prefer to stick with the imperfect yet irresistible Autobiography).