鈥楲atest plan of the North Sea island of Borkum'. Borkum is the largest and westernmost of the East Frisian Islands in the North Sea; off the coast of East Frisia in Lower Saxony; Germany. ; With picture postcard illustrations inserted. The story is set in the Frisian Islands. The 鈥楻iddle of the Sands' is an early example of the espionage novel and is one of the "invasion" novels that raised British public's awareness of the potential threat of Imperial Germany; and as a result the Royal Navy developed several bases on the North Sea coast of the British Isles to prepare for the possibility of war with Germany.T. Nelson & Sons: London & Edinburgh; [1910.].From: Erskine Childers; The Riddle of the Sands. A record of secret service.012646. c. 37 after page IXLondon; British Library.