 Bodyguard of Lies opens with an introduction to Ultra, the codename for decrypted signals intelligence. It goes on to document the origins of the London Controlling Section (LCS) and the work of Dudley Clarke in the Middle East. In late 1942, Allied high command in London became aware of Clarke's successes during the North African Campaign. Based on his theories of deception, the LCS was created under Colonel John Bevan and granted broad powers to plan deception strategy. The introduction finishes with a discussion of how the Allies evolved deception strategy prior to 1943, including the Double-Cross System (the Allied system of double agents). The second section of the book introduces the German intelligence forces, in particular Admiral Canaris and his Abwehr intelligence agency. Brown discusses early deceptions, such as those surrounding Operation Torch, conducted against the Germans, and how the Abwehr struggled to decipher the information it was being fed.
