"Who?" asked Franz, and this time he lowered his voice to the desired pitch. "Are there some Germans up ahead? Did the blowing up of our dugout mean that our lines are smashed?" His voice was anxious. He and Bob could not see beyond the place where Roger and Jimmy had come to a halt. "Just wait a minute," advised Jimmy, still keeping to a whisper. "Rodge and I just saw something that may be all right, and may be all wrong. We're going to see what it is. We'll tell you when we come back. Stay where you are with Iggy. It may not be safe to go on any farther." Bob and Schnitzel let Iggy lean up against the tunnel wall. The Polish lad closed his eyes and made himself as comfortable as possible. His two companions looked ahead along the dark shaft which connected the two former German dugouts. They could dimly see Jimmy and Roger moving ahead, now and then cautiously flashing their pocket torches. And the strange sight that had so startled the two leading Khaki Boys was this. In the second dugout, which did not seem to have been much damaged by the blast that, for a time, had buried the Khaki Boys, Roger and Jimmy saw four men. They stood in the middle of the old dugout, which had not been used in some time, and on a table, about which they were congregated, burned a candle stuck in the neck of a bottle. But the curious fact about it all was that while two of the men wore the regulation American army uniform, the other two were in civilian attire. And it needed but an instant's thought on the part of Roger and Jimmy to make them understand that there was something vitally wrong here. Civilians were not only not supposed to be so far within the front lines, but they were actually forbidden. It was against all military rules and regulations. No one without a uniform was allowed so near the front--even the newspaper correspondents being rigidly required to conform to certain rules in this respect. The reason for this was obvious. So stern were the necessities of war that it was imperative that each man bear some distinctive mark. He was either a friend or a foe, and the only way this could be told, where there were so many thousands, was by a uniform. Of course, the wearing of a uniform did not guarantee that the man inside it was a friend. He might be a spy. But the appearance of men in civilian garb within the army lines caused suspicion at once. And this suspicion was at once engendered in the minds of Roger and Jimmy. "What do you think of that?" whispered Roger. "I don't think very much," was Jimmy's answer, as they paused at an angle in the tunnel and gazed forward into the candle-lighted dugout. "It looks bad to me." "That's what I say. Those are two doughboys, or some of our Sammies, anyhow. As for the other two--say, I haven't seen anyone in civies for so long it looks strange. What do you think those two civilians can be doing there talking to two of our men?"