"Yes," replied Max thoughtfully. "You're referring to Schenk's threat that, if ever the Germans had to leave Liege, he would smash up the works so thoroughly that not one brick would be left upon another?" "Aye." "He's just the man to do it." "He is that. And the less reason for you to bother about the place. It's no use worrying; it can't be helped." "I'm not so sure. Anyway I'm going to do what I can to save the place. As for these papers of Schenk's, I'm going to hand them over to the British consul. They'll be useful, I don't doubt, as one more proof of Germany's deep-laid plans for war." Max did as he proposed, and the papers were accepted with alacrity and forwarded to the British Foreign Office. At the same time Max made application on his own and Dale's behalf for employment in Belgium as members of the British Secret Service. After a week or two's delay, during which time enquiries no doubt were being made into their credentials, an official arrived with the necessary documents, and after a long conversation, detailing exactly what was required of them, Max and Dale were accepted and enrolled. A few days later they had said good-bye to their home in quiet Maastricht and were away across the frontier, in the great whirlpool of the war once more. They resumed the disguises of Walloon workmen, which had already served them in such good stead, and applied for work in Liege and all the big towns of Belgium. For two years and more they worked steadily, in different workshops up and down the country, gathering news and transmitting it faithfully to the agents of the British Government. They were cool and reliable observers, and their information was found to be so uniformly accurate that it was relied upon more and more as the months went by. CHAPTER XXI The Great Coup At the commencement of their work in the Secret Service, Max and Dale visited Liege, and, while collecting information there, thought out and put into operation a far-reaching plan that they hoped might checkmate Schenk's schemes for the destruction of the Durend works when the Germans should be forced to evacuate the city. It was a plan formulated after they had again got into touch with M. Dubec and the small band of men who still loyally refused to work in the interests of the invaders. M. Dubec had imparted to them the information--not unexpected--that Schenk had placed mines under all the workshops, and put everything in readiness for blowing them into the air whenever he should wish to do so. "I have it from one of the men who actually helped to dig and fill them, Monsieur. He was not allowed to help in the wiring, and he believes this was done secretly at night, by Germans whom Schenk knew he could trust." "So you know that the shops are mined, but do not know where the wires run?" "That is true, Monsieur." "Could you not find out?"