The Spy Net by Henry Landau

The "White Lady" spy net stretched across Europe, encompassing more than one thousand agents and producing 70 percent of Allied intelligence on the German forces in the First World War. Through sheer ingenuity, it maintained a staggeringly complex network of spies deep behind enemy lines, who provided vital information on troop movements to and from the Western Front. Its success rested on one man: Henry Landau.

After the war, Captain Henry Landau left the Service and during the 1930s wrote several books about his time as a spy, published only in the United States to avoid prosecution under the United Kingdom Official Secrets Act.