Book excerpt: With the fall of France, almost the entire coastline of Western Europe was in German hands. Clandestine sea transport operations provided lines of vital intelligence for wartime Britain. These 'secret flotillas' landed and picked up agents in and from France, and ferried Allied evaders and escapees. This activity was crucial to the SIS (Secret Intelligence Service) and the SOE (Special Operations Executive). This authoritative publication by the official historian, the late Sir Brooks Richards, vividly describes and analyses the clandestine naval operations that took place during World War Two.