Out in the open, and especially in the mountains, distances are deceptive. Jerry and Slim learned this when they had been traveling for two hours, and the point where they had seen the last German disappear over a hilltop seemed as far away as when they started. "Ever travel along in a train at night watching the moon, and notice how it seemed to move right along with you?" asked Jerry. "Lots of times," answered Slim, as he puffed along, "Why?" "Well, that's the way that hill seems to be traveling along, always keeping the same distance ahead of us." "I've heard of armies 'taking' a fort, or a city, or a trench," said Slim. "Do you suppose those Germans are 'taking' that young mountain along with them?" "Seems so to me," said Jerry, coming to a halt to shift the heavy pack-set to the other hand. As a matter of fact, early evening--a cold, biting winter evening--was settling about them when they finally climbed to the crest of that hill to cautiously "see what they could see." Far beyond the slope ahead of them, in the dim dusk, they could discern a mass of men, evidently halted for the night. "That's their rear guard," announced Jerry, with the field glasses to his eyes. "I can even make out their sentries." Slim took a look and agreed. "Hadn't we better report?" he asked. "I think we ought to make this bunch of trees here our position, and then scout ahead a little first," said Jerry. "All right," Slim agreed. "Which one of us shall go?" "Let's toss." They did, and it fell to the lad who had claimed to have the scent of a deerhound to go out and reconnoitre, while the "natural-born scout" remained behind. Divesting himself of all his burdens but his revolver and ammunition belt, Slim started off. Leaving Jerry to arrange their effects, he gave that young man a real shock when he silently returned five minutes later unheard by Jerry, and, standing only half a dozen feet behind him, blurted out: "Forgot my field glasses." Jerry whirled around as though he had been shot. "Why don't you sneak up and try to frighten a fellow to death?" he demanded. "Sorry," Slim apologized. "Thought you heard me coming." "I believe you did it on purpose," Jerry growled, as the other youth again started off. "I'll send in my card first next time," was Slim's parting remark. "Well, be sure to make yourself known," retorted Jerry, "or I might mistake you for a Boche and send in a bullet." Slim's laugh floated back and he disappeared down a ravine through which he was making for a higher point of observation further on. Ten minutes elapsed and there was no sign of Slim. When a quarter of an hour had passed Jerry began to get worried. Had his friend perhaps fallen and injured himself? Had he lost his way? A dozen fears came into Jerry's mind, and at the end of another five minutes he decided that it was time to take some measure to learn the whereabouts of Slim. Softly, but with great carrying force, he gave the well-known "Whip-poor-will."