The story of how British intelligence set up a bogus German spy ring manned by ex-German spies and pumped fake intelligence into the Abwehr has been told and told again, but here it is from the horse's mouth, amplifying the recent telling by Farago in Game of the Foxes (p. 1289). Masterman, now an Oxford history don, ran the double-cross Double-Cross operation for MI-5; this book is an adaptation of his 1945 aide-memoire summing up the program. Its charm is dryness, in contrast to Farago's gush, and unless one is passionately addicted to inside stories the chronological, stiffly-understated narrative soon daunts a thirst for adventure. Of interest, however, are Masterman's prescriptions for running a spy network of this exceptional ""turn-around"" type, the precautions necessary, the attention paid to individual psychology, and to details of each counterspy's cover story. ""A lie when it is needed will only be believed if it rests on a firm foundation of previous truth""; hence every aspect was carefully coordinated by a ""case officer"" assigned to a particular double-cross agent: Most of the 120 agents were German spies dropped into England and then, usually under pain of death, persuaded to work for the British. Masterman displays a strong touch of sang-froid in describing which spies were chosen to be executed to make the other agents ""believable"" to the Germans. Minute record-keeping was required to make all details consistent with each cover story, although Masterman was chagrined at the crude incompetence of his Abwehr opponents, who failed to detect a phony spy even when the British decided to blow a double-cross agent's cover Less dramatic than other accounts, but assuredly more complete and authentic.