But this was not so easy a matter as he thought. The old castle proved to be a perfect maze of rooms, some connected and others detached, and again and again he found himself going further away from the sounds and having to retrace his steps. Then too he was afraid to flash a light, and had to grope his way over the uneven floor and amid piles of debris. At last, however, he found himself on the right track. A faint ray of light from a distant room gave him the clue. Moving with the stealth of an Indian on the trail, he crept forward until at the end of a distant corridor he found what he sought. In a large room, lighted by a fire that blazed on the hearth and by three or four candles, were a number of men engaged in animated conversation. A glance at their features showed that all were Germans. Some of the men were in civilian clothes, but others wore old, dilapidated army uniforms. They were a rough looking lot, and Bart saw at a glance that most of them were armed. They were gathered about a man with a red, bushy beard, who seemed to be the leader. He had a map spread on a table improvised from boxes, and was pointing out places indicated by red dots. Bart counted the men. There were nine burly fellows, who looked desperate and as though they could give a good account of themselves in rough and tumble work. In one of the guns standing against the wall Bart noted a red flag thrust in the muzzle--the symbol of the German revolutionary element that was spreading terror throughout the former empire. He could hear distinctly now what the speakers said, but his knowledge of German was limited and he could not get the full meaning. He heard repeatedly however the words "Coblenz," "Liebknecht," and "Spartacide." He knew what was meant by those baleful words. They meant the overthrow of law and order, a program of blood and massacre. And they were discussing this program evidently with reference to Coblenz, where the American Army of Occupation had its headquarters. Bart pondered what he should do. It was out of the question for him alone to attack these conspirators. They were too many for any single man. He must arouse his comrades at once. With the utmost caution he tiptoed back, and finding the room, not without some difficulty, bent over the sleepers. They were dead with sleep and he had to shake them to get them wide awake, but the news he whispered to them had them on edge and ready for action in an instant. They crowded together for a whispered conference. "What would we better do?" asked Billy. "There's just one thing to do," said Frank, "and that is to nab the whole bunch. That is," he went on, "if we find that they're really hatching mischief, as Bart thinks. I've picked up enough German in the last few months to be able to understand what they're talking about, and on a pinch I could even talk with them after we've got them under our guns." "But are you sure we have any right to arrest them?" asked Bart, a little doubtfully.