Nick Carter took up the matter as if it were merely a petty theft, instead of one threatening the nation. No need to tell him, nevertheless, of the terrible danger from further construction in accord with the stolen plans, or of the vast expense and innumerable difficulties in changing them, they presumably having been made to the best advantages discernible to the expert government engineers in charge of that part of the work. One scarce could conceive of a more serious and possibly far-reaching loss. Nick gazed at Chief Welden for a moment, then asked tersely: “Any clew?” “None, so far,” was the reply. “You suspect it was the work of the spies mentioned?” “Naturally.” “Who is on the case?” “Several of my best men,” said Welden. “I have talked with the president, who is much disturbed by the matter, and we realize that these men may be known by sight and that they are connected with the secret service. We have thought wise, therefore, to employ you on the case, assuming that you are not known and can work to greater advantage. There is this much to it, Carter,” he forcibly added: “Those plans must be recovered. They must be found before copies can be made, or----” “One moment,” Nick interposed. “I appreciate all that is involved. It is bad, terribly bad, but I will do my best to meet the situation. Send for Garland. I wish to question him.” “I think I can answer any questions that----” “You won’t do,” Nick again interrupted. “I might ask questions that you could not possibly answer. I shall want them answered. Send for Garland. I wish to talk with him.” Chief Welden turned to his desk and rang for the clerk in the outer office. CHAPTER II. THE GOVERNMENT ENGINEER. Nick Carter was a keen physiognomist. He no sooner saw the face of the young man who entered Chief Welden’s office a little later, than he was sure of his lofty character and sterling integrity, as Welden already had asserted. He was tall and erect, with the carriage of a soldier and set up like an athlete. His smoothly shaved face was of a classical cast, with clean-cut, regular features, a fair complexion, and frank blue eyes, with a broad brow and wavy brown hair. He then looked white and drawn, however, as men look who have aged years in as many days under some terrible experience. Mental distress of the most poignant kind was reflected in his face, and Nick rightly inferred, as Chief Welden also perceived, that the young man apprehended further direful disclosures and additional misery from this unexpected summons to the chief’s office. Welden hastened to reassure him, however, by saying, with sympathetic voice and a smile: “Draw up a chair, Garland, and shake hands with this gentleman. We have brought him from New York to pull you out of this affair. I think he may succeed in doing so, for he rarely fails, if ever, in what he seriously undertakes. His own mother would not know him just now, however. Shake hands with Nick Carter.”