Five years following her son’s apparent suicide, Sara Turing sought to paint a sympathetic, human portrait of her brilliant, troubled son. The Alan Turing she describes, the man of Turing Machine fame of which other biographers have written, is her Alan, a beloved, dead child.

When this biography was written, Alan Turing’s contributions to the Allied effort to defeat the Axis in World War II were restricted by secrecy. Little is lost by these omissions, however, because the author’s intention is not to write a scientific appraisal. Sara Turing divides her book into two parts. "Part I. Mainly Biographical", begins with a lengthy genealogical review of the Turing family. She takes us sequentially through Turing’s childhood and early education at Sherborne School, to his undergraduate days at Cambridge, to the Graduate College, Princeton.

The unclassified stories of Turing’s wartime work at the National Physical Laboratory, Teddington, and his contribution to the Manchester Automatic Digital Machine, are interesting. The author also tells us of Alan’s considerable talent as a long distance runner, which surprised me. Technical description of his scientific work is included in "Part II. Concerning Computing Machinery and Morphogenesis."

Turing died at the age of 41. While working to create a non-poisonous weed killer and sink cleaner, he ingested potassium cyanide, possibly via a contaminated apple. I refer mystery fans to page 115.