Against these covert forces working for the destruction of our civilization, our Government developed an unsuspected efficiency, sometimes through its department of justice, sometimes through a vast and silent civilian body of detectives working all over the country and again through its franker agencies of the military arm. Thus that able engineer who had built the great power dam here at the Two Forks--a man who had built a half score of railroads and laid piers for bridges without number, and planned city monuments, with the boldest and most fertile of imaginations, Friedrich Waldhorn his name, was a graduate of our best institutions and those of Germany--long since had been watched as closely as many another of less importance in charge of work remotely or intimately concerned with the country's public resources. Waldhorn--before the war an outspoken Socialist and free-thinker--may have known that he was watched--must have known it when a young medical officer given military duties quite outside his own profession, was put over him in authority at the scene of his engineering triumph, and at precisely the time of its climax. But the situation for Waldhorn was this, that if he resigned and left the place he would only come the more closely under immediate espionage. Whatever his motives, he remained, sullen and uncommunicative. Meanwhile the little camp sprawled in the sun, scattered along the plateau on the side of the mountain gorge. Crude, unpainted, built of logs or raw boards, it lay in the shadow for the greater part of the day, deep down in the narrow cleft of the mountains, far out in the wilderness. The great forest deepened and thickened, back of it, forty miles into the high country. Those who lived here in the canyon could not as yet understand the nature of the thin blue veil which today obscured their scanty sunlight, did not know that each minute of day was destroying trees which had cost a thousand years to grow, which never in the knowledge of man might be replaced. But when the party of Major Barnes came down from Sim Gage's ranch, questions were answered. The forest had been fired again. The soldiers swore the silent soldier oath of revenge. Doctor Barnes did not pause even to help the women out of the car. He hurried to the long, screened gallery in front of the residence and office of Waldhorn, chief engineer. Waldhorn met him at the door, well-fed, suave, polite, a burly man, well-clad and bearing the marks of alertness and success. Always of few words, he scarcely more than spoke at present, his mildly elevated eyebrows making inquiry of the dusty man before him. "Yes, Doctor, or--ah, Major?" he said, smilingly, insulting. "Call it Major!" snapped Barnes. "I've come to tell you that I want your house." "Yes? When?" "In two minutes." "Why?" "I want it for Government uses. A patient of mine has come down here to stay a while--wife of one of my scouts."