After Hitler reluctantly halted his proposed invasion of Britain in the autumn of 1940, he immediately ordered, by secret edict, the building of an Atlantic Wall. It was a monumental task--made up of 1,500 steel and concrete defensive strongpoints, stretching over four coastlines--and completely designed by the Führer himself. Using material from British, American, and Canadian archives, one of today's top military historians pieces together a unique, barely known story from the war--and memorializes the Allied soldiers caught behind it in appalling conditions.