We have had a certain amount of experience of the German spy and his devious ways, but in France--the first country that the Huns had earmarked for destruction--the espionage system was even more fully developed. Ever since the beginning of the war the writer of this remarkable article has been engaged in collecting authentic information concerning German spies and their methods, and some of the results of his investigations are set forth. A startling light is thrown on the ramifications of a system that employed abroad more than sixty thousand men and women in every walk of life, and which is still far from having been eradicated.--Related in _Wide World Magazine_. I--STORY OF A STARTLING DISCOVERY AT MONTE CARLO In the early days of the war, when everything in the military and civilian life of France was still in a state of perturbation, certain undecipherable messages were picked up nightly by the wireless telegraphy station at Cros-de-Cagnes, a little fishing village on the French Riviera, some seven miles from Nice. Other stations in many other parts of the country and abroad likewise received those mysterious fragments from the unknown--partly in code, partly in unintelligible German--and transmitted them to military headquarters, where futile attempts were made to make head or tail of them. One thing, however, was certain: they emanated from an enemy source, a secret wireless installation somewhere, as the experts were convinced, either on the French or Italian Riviera. The problem of the whereabouts of the German or Austrian spies who thus dared to carry out their nefarious operations under the very noses of the French and Italian authorities at once became of intense interest to the police all the way between Marseilles and Genoa. But they searched for the culprits in vain. Before the middle of August, 1914, however, thanks to a perspicacious English journalist, the mystery was elucidated.