Returning to the barracks as Frank had proposed, they found that a list was posted on the company bulletin board, and carefully scanned it for Tom's name, while fear tugged at their hearts. Great was their relief when they failed to find it, for if he were only a prisoner the chances were that the authorities would get him back, or that the boys themselves might ferret out the place where he was being held and rescue him. "Well," said Bart, as the boys turned away from the bulletin board, "there's not much we can do for poor Tom to-night, but if he's a prisoner we'll get word from him sooner or later." "If he's a prisoner, I'd hate to be the man who has him in charge," remarked Billy grimly. "Something pretty terrible is apt to happen to that bird most any time." "Yes, chances are he'll come marching into camp with a few prisoners on his own account." said Frank. "That is, if he doesn't catch this new disease they're talking about," "What disease?" asked Billy. "I hadn't heard anything about it." "Nobody seems to know very much about it," replied Frank. "It has appeared at various places in Germany, especially in the occupied zones. It seems to have attacked Germans as well as Americans, and nobody knows what to make of it. Of course, remember I'm only telling you what another fellow told me recently, and I give it to you for what it's worth. It may be just rumor, but he seemed to be so certain of his facts that I felt inclined to believe him." As it happened, what Frank had heard as a rumor was indeed a fact-- and a fact, moreover, that was proving most puzzling and unpleasant for the American medical authorities. The disease that Frank had spoken of had indeed made its appearance in various parts of the country, and while the doctors had many theories concerning it, they were all only theories as yet, and nothing really definite was known regarding it. The symptoms were much like those of virulent typhus. Men sickened and died within forty- eight hours, and once stricken, the unfortunate victim did not recover in one case out of a hundred. Some of the doctors were inclined to think it one of the plagues that usually follow in the track of war, due to privation and depression. This theory, however, did not explain why American troops, well fed and victorious, should be affected. Most believed it to be caused by some deadly germ, hitherto unknown, and every effort was being made by the medical corps to isolate the germ and find a remedy for the disease. But the Army Boys were to know more of the source of this strange scourge and make a most amazing discovery regarding it. CHAPTER XIV ON THE TRAIL On the day following that of Tom Bradford's disappearance, Bart and Billy were assigned to special duty as part of an officers' escort on a mission to a neighboring town.