"I have a notion, Madame Gilbert, which I should like you to follow up," said Dawson. He was at that time (the Spring of 1915) in his office in London--he had not yet been despatched on his spacious pilgrimage to the northern shipyards--and Madame Gilbert sat opposite to him in an attitude deliberately provocative. She sat back in a comfortable chair facing the light, her legs were crossed, and she displayed a great deal more of beautifully rounded calf and perfectly fitting silk stockings than is usual even in the best society. Although she did not look at Dawson, she was fully conscious of the frowning glare which he threw at the audacious leg. "Please give me your attention--if you can. I have been out at the Front lately, at General Headquarters, to advise upon the means of stopping the flow of information from our lines to the enemy. All the obvious channels have been stopped--the telephones hidden in French cellars, the signals given by the hands of clocks, the German spies dressed in uniforms stripped from our dead, and so on. Lots of them, all obvious and simple. One can deal with that sort of thing by a careful system of unremitting watchfulness. We must have caught up with most of the arrangements made by the Germans before the war, but they still get much more information than is good for them to have, and for us to lose. I am convinced--and G.H.Q. agrees--that there are many officers, especially in the French and Belgian armies, who were planted there years before the war for the precise purpose to which they are now put. Even in our own Army, which is expanding so rapidly, the same thing is possible, even probable. An infantry officer spy can do little--he knows nothing of the Staff plans, and cannot get into communication with the enemy at all readily, without arousing suspicion. I went into the whole thing at the Front, and I put my finger, as I always do, upon the danger spot--the Flying Corps. Those who fly constantly over our own and the enemy's lines have complete information as to distribution and movements, and, if they choose, can drop dummy bombs containing news for the enemy to pick up. A French, Belgian, or English aeroplane 'observer' in the enemy's secret service could convey information to him at pleasure and without the possibility of detection. I don't suspect our own Flying Corps, except on the general principle of suspecting everybody and everything, but I do that of the French and the Belgians. France and Belgium were salted through and through by the Germans in anticipation of war. There in the Flying Corps we have a very grave danger which--But I see that you are not attending, madame," he broke off angrily. Her eyes withdrew from the offending leg for an instant, and flashed at Dawson with a penetrative power which even he felt. "Shall I repeat what you have said, word for word?" asked Madame Gilbert coldly.