With only a few good men and women, and in spite of the unrelenting pressure of both German and Vichy security services, the BCRA managed to establish a series of resistance networks that eventually provided up to 75% of the vital intelligence needed for the preparation of the June 1944 Normandy landings. Based on little known or ignored documents, this latest addition to the Resistance series presents General de Gaulle's secret services that went from being no more than a small band of amateurs in 1940 to a key element of the Free French contribution to final victory.