Nigel West and Madoc Roberts certainly produced a fine toothed and focused history of this rather dubious individual. This volume keeps to a rather dry, factual style. It is well informed and the quality of the research comes clearly through. For understanding how one individual came to help the British Secret Services develop their doublecross programme, there is not enough context of Snow’s life, really. However, this weakness is also its strength in trying to untangle the know of just who this person was and who’s side he was on. In the end, I would agree with these authors. A bit more context would only have helped flesh this volume out. As it stands it is the better of the two Snow books I have read, although James Hayward’s volume (hardback Double Agent Snow or paperback Hitler’s Spy) does produce more context his style undercuts the value of his own work. Masterman’s book is written by the master of the doublecross system and thus should round out the ideas and practicalities of how the system was more generally applied.