One day during World War Two, Thomas Argylle "Tar" Robertson, a member of England's MI5, sat back to look at the big picture. And he realized that he and not the German Abwehr controlled all the German spies in Britain. All of them. The Germans thought they had a large network of agents in the British Isles. Every one of these agents was either an agent for the British or fictional.
It began to dawn on Robertson that he could do something with such control over the information being sent to the Germans. And so began the project called "Fortitude" which attempted - and succeeded in its attempt - to convince the Germans that the D-Day invasion would take place at Pas de Calais.
The project was overseen by a committee called the Twenty Committee (XX, double cross, twenty - get it?) run by John Masterman, better known to us perhaps as the author of the 1933 mystery, An Oxford Tragedy. The name of the committee is a hint at the language, puns, wordplay, that the men in British Intelligence loved. They all, especially Masterman, also loved cricket.
The relationship between cricket (that most English of sports) and spying (at which the British have always excelled) is deep rooted and unique. Something about the game attracts the sort of mind also drawn to the secret worlds of intelligence and counterintelligence -- a complex test of brain and brawn, a game of honor interwoven with trickery, played with ruthless good manners and dependent on minute gradations of physics and psychology, with tea breaks.
During the course of the war MI5's agents (including Agent Zigzag, the subject of an earlier Ben Macintyre book) fed the Germans "chicken feed," the term they used for useless information. Included as well was incorrect information. Tar Robertson realized that with the D-Day invasion coming in another year, it might be very useful to encourage the Germans to believe that it was to take place at another time and place than was actually planned.
The men and women of MI5 were unafraid of the unusual or seemingly ludicrous, like their use of pigeons, trained to be double agents and infiltrate German pigeon coops. Even before the war it was "realized that Britain was falling behind Germany in the pigeon race." The Pigeon Service Special Sector B3C, run by Richard Melville Walker (a Flight Lieutenant, of course)
. . . was convinced that Nazi pigeons were now pouring into Britain, by parachute, high-speed motor launch, and U-boat, providing enemy spies in Britain with an undetectable method of sending information to occupied Euroope. Walker was not alone in his pigeon paranoia: Basil Thompson, the veteran Scotland Yard spy catcher, observed: 'It was positively dangerous to be seen in conversation with a pigeon.' Some experts claimed to be able to identify a pigeon with a German 'accent.'
Eventually some peregrine falcons were trained to catch enemy pigeons. Unfortunately they caught only British pigeons, a sort of avian "friendly fire."
How did these people keep their sense of humor in the midst of the horrors of war, operating as they were "in that grey area between ingenuity and insanity"?
As D-Day came closer, MI5 and the Twenty Committee sent increasing numbers of messages reporting a large force under Patton collecting in the southeast of England and preparing to invade Europe at Pas de Calais. They hired an actor to impersonate Montgomery. They built rubber and plywood tanks and aircraft that looked real (or that they hoped looked real) from above. By the time D-Day actually happened they had the Germans so convinced that Normandy was just a feint and the real attack was to come at Pas de Calais that it was seven weeks before the enemy sent the forces protecting Calais south to contend with the Normandy invasion. Some Germans never did believe they had been taken in by a hoax.
The techniques of identifying possible agents, turning enemy agents to work for Britain, and managing the often eccentric people on whom they were depending for this important work is the heart of the book. A Serbian playboy, a Peruvian socialite, a Polish patriot, a Spanish chicken farmer, and a French woman more concerned about her pet dog than about the invasion -- somehow MI5 had to keep these people focused on the work at hand.
This is the third of Macintyre's three books about spies and the D-Day deception, the others being Agent ZigZag and Mincemeat. All three are first-rate.