This interpretation of Montgomery’s exploits is based upon Ronald Lewin’s magnificent work, Ultra Goes to War, published by McGraw-Hill Book Co. in 1978. This work was also commissioned by the author while he was an editor. In later years the author showed Lewin some of the research for this current work. Lewin said he was unaware of many of the documents he was being shown, but he believed they “were pure dynamite.” Speaking about Magic at Bletchley Park in Ultra Goes to War,