After a few days' more planning, and another consultation with Dubec, the details of the scheme were settled to everyone's satisfaction, and the work commenced. The direction of affairs on the spot was left to Dubec, and to him was also left the responsibility of deciding to what men the secret should be imparted. Then Max and Dale left the district and went on with their own special work, satisfied that the last and final stratagem for defeating Schenk was in good hands, and likely, in the course of time, to be brought to a successful issue. It is not here that we can describe the many adventures that befell Max and Dale while in the British Secret Service. They were numerous and exciting enough, but this tale deals primarily with the fortunes of the great Durend workshops and their influence in the war. A long, tedious period of trench fighting now began on the Western Front. There were no big territorial changes, although there were many attacks on a grand scale at Ypres, at Verdun, on the Somme, and in the plain of Flanders. But this period, tedious though it was, came to an end at last in the great German retreat. Then came for Max and Dale the crucial period of all their long and patient scheming to outwit their own special enemy, Otto von Schenkendorf, the manager of the Durend works. When the great retreat began, Max and Dale were at Liege, on the spot. At the gates of the works they watched the serried ranks of workmen and workwomen as they trudged out in response to the manager's orders that the works must be closed and that all workers of German nationality or sympathies must retire across the frontier. The anger and consternation in their faces were a treat to see, after the long years of their arrogance towards men and women of Belgian nationality. The war was virtually over--so said their faces--and many of them were doubtless dreading lest infamies, similar to those wreaked on the helpless Belgians, might be perpetrated in _their_ towns and villages. As the crowd thinned, Max and Dale caught sight of the manager, accompanied by a German officer, seated in a great grey motor just inside the gates, apparently waiting for the last workman to file out and away. The guard of soldiers was still there, standing stiffly to attention, and it seemed to Max that there was an air of tension about them all, as though something was about to happen. He could well guess what. Suddenly, in the distance, there came the sound of dropping rifle-shots. "They've cut it pretty fine, if those shots mean the advance guard of the Allies," remarked Max in a voice tense with excitement. "The works are clear of the workmen; now for the last great act. Then the curtain!" Herr Schenk--as we shall continue to call him--stood up in his car and shouted to the officer of the guard: "You have your instructions, Lieutenant. Act upon them now without delay." The officer saluted, turned about with military precision, and strode into the guard-room.