For German gold the Bixtons had betrayed their country, they had indicated the secret location of batteries and other engines of war, enabling the Huns to land their destroying shells accurately. The Bixtons, by means of the smoke signals to which they had access and which they could send up secretly, had given the Germans the exact information they wanted. And Ammann and Anker were German spies--the go-betweens. "_Ach!_ For the Fatherland!" exclaimed Anker, as he extended his hand for the bundle of papers Jimmy held out. "I do this for the Fatherland!" "And I do this for the good old U. S. A.!" cried Jimmy in ringing tones as he leaped to his feet and brought the butt of the rifle down on the head of Anker. At the same time Jimmy yelled: "Let him have it, Roger!" And Roger dealt Ammann a smashing blow, so that the two German spies slipped from their chairs together to the floor of the cave. They were now as helpless as were the Bixtons. CHAPTER XXIV THROUGH THE LINES "Great work!" cried Roger, as he and Jimmy, lighting the lamp again, made sure that the two Germans, as well as the American traitors, were unable to give further trouble. "Yes, luck was with us all right," assented Jimmy. "But, oh boy, what a lot this amounts to!" "You mean finding out about the smoke signals plot?" "Yes, and all that it takes in. You wouldn't think there could be such skunks on earth as those Bixtons, would you?" "I should say not!" agreed Roger. Though the traitors were gagged their ears were open, and if they had a spark of manhood left they must have squirmed. "You can't blame the Germans so much," went on Jimmy. "They were working for their country, not against it, and they probably thought what they did was all right. But it was up to us to put 'em out of business." "And I guess you did to the one you hit all right," said Roger. "Looks as if he was done for." "Couldn't be helped," was Jimmy's grim reply. "It was the spies or us. How's your man?" "Well, I hit him pretty hard." This was evident. Spurred by the necessity for acting with vigor and promptness, the Khaki Boys had struck hard. Both the Germans were unconscious, and, as developed later, one was so badly hurt that he died. "Well, what's the next move?" asked Roger, as they sat down and looked at one another. Their nerves were a bit unsteady, and no wonder. They had passed through a strenuous time in the last fifteen hours. "We've either got to take these fellows somewhere to give them up to the army authorities, or get word to our boys that the scoundrels are here," Jimmy said. "There may be more of the signal corps men involved in this spy work, and it ought to be known. But I don't see how we can very well take all four to our lines, provided we can find the lines. This fellow," and he pointed to the badly injured spy, "can't walk." "Why not leave these two here in the cave, tied as tightly as we can manage?" suggested Roger. "What about the Bixtons?" Jimmy asked.