This first of two volumes, an Edgar nominee, explores the seemingly chaotic, undated, and sometimes barely legible notebooks in which Christie interspersed ideas, plot outlines, and casts of characters for her novels, plays, and stories with shopping lists, reading lists, and other ephemera. Curran, an Irish literary adviser to the Christie estate, organizes it all with admirable thoroughness, often bringing together material on a given title scattered among several notebooks. The arrangement is mainly topical, bringing together titles with a theme or type of background in common. Though the inclusion of two previously unpublished Poirot stories serves to attract a wide audience of fans, the real appeal of the book is to specialists and scholars. Solutions are routinely revealed, with warnings in the chapter headings. Curran’s critical differentiations add to the interest.