The book of course discusses in detail Alan Turing's seminal On Computable Numbers paper, as well as his involvement in the breaking of German cryptography (and the Enigma machine) during World War II, but also paints a very intimate and human picture of Alan Turing, a picture which includes character flaws and vulnerabilities. Contrarily to what I had assumed based on my introduction to Turing Machines in computer science classes, Alan Turing was not just a pure theoretical mathematician. I would recommend this book to anyone who's curious to know more about Alan Turing, or just interested in reading a good biography.