The Flying Machine Boys on Secret Service. Frank Walton

all!” the boy mused. “It’s just a signal station, and the operator is probably wrapped up in fur overcoats a foot thick. I guess about all I can do here,” he went on, “is to see if there is another fire in sight.”

      The western slope of the ridge was much steeper than the one he had already ascended, so at times the lad approached the hostile camp-fire a great deal faster than he wanted to. He tried to proceed cautiously, without making any noise, but now and then when his feet slipped and he rolled half a dozen paces, to be caught at last by a little crevice or a narrow shelf, small rocks became dislodged and went thundering down.

      “Might just as well take a band,” Jimmie mused disgustedly.

      When the boy came to within a few yards of the fire he saw that only one figure was in sight. As he had predicted he would be, the lone guardian of the fire was well bundled up in furs. If the motors had attracted his attention his manner gave no indication of the fact.

      “Looks like a wooden Indian,” chuckled Jimmie.

      There was no place for the boy to secrete himself in the vicinity of the fire, so he crouched down on the slope and looked over the landscape beyond. He could see his own camp-fire quite distinctly, but no other light was in sight for several moments.

      Then what seemed like the blood-red light of an early August moon showed on a level of rock far off on the west side of the valley.

      “They’re burning red fire over there, too,” he mused as the situation became clearer in his mind.

      The boy climbed back up the slope for a few yards and looked again, but the fire itself was not in sight and only the reflection showed on a slender surface of rock beyond. While he looked the color changed to green, which showed indistinctly under the stars.

      From his new position Jimmie could see his own camp to better advantage than from the one lower down. He sat watching it for some moments, wondering why Ben was moving around the blaze so actively and why Mr. Havens had left the tent.

      There certainly were two figures outlined against the blaze. The lad studied the puzzle intently for a moment and then started back. He understood that it would be of no use for him to try to get nearer to the fire below. The man on watch there would be conscious of his approach before he was within a hundred feet.

      From the ridge the boy looked back to his camp again. There were now four figures outlined against the blaze, and all appeared to be moving about as if acting under great excitement.

      Jimmie tried his best to discover whether any of the figures were those of Mr. Havens and Ben, but the distance was too great. He could only see the figures moving about. As he looked and studied over the proposition he blamed himself for not bringing his field-glass, but his self-reproach was, of course, unavailing.

      Knowing that he ought to be making his way back to the camp, the boy still remained gazing downward as if fascinated. He had no reason to believe that the visitors he saw were at the camp with friendly intent. He knew that his friends might be in great danger. Still, he sat and watched the fire like one dazed.

      There had been no sound of motors, yet the intruders at the camp had penetrated the valley since nightfall. Or had they been hiding there at the time the boys landed? While the boy puzzled over the situation a mass of rocks left the summit not far to the north and went racing down the slope, making sufficient noise, as Jimmie believed, to incite a riot a hundred miles away!

      “Now there’s some one sleuthing in that direction,” the boy mused. “Of course, he was at the camp-fire when he heard the motors and ducked. Now he’s up there watching me, I presume.”

      The lad turned toward the snow-capped summit once more, resolved to get away to his own camp as soon as possible. When he reached the top the clatter of motors came to his ears. He looked down in dismay to see the Louise lifting into the air.

      “Now, what’s that fool Carl doing?” he muttered.

      The aeroplane left the shelf with a little dip over the precipice and struck out for the west, passing nearly over the wondering boy’s head. The acetylene lamp which had been arranged on the forward framework was burning brightly, and Jimmie could see that both seats were occupied. The lamp had been turned low just before his departure.

      The boy paused at the summit and looked back into the valley. There was no need now for him to cross to the eastern slope. He had no doubt that the Louise had been stolen, and that Carl was driving her away under duress. In order to reach the camp he would be obliged to pass down the steep slope which led to the bottom of the valley.

      Blaming himself for leaving the machine even for a moment, yet by no means disheartened at the calamity which had overtaken him, the boy turned his face to the south resolved to pass along the broken summit until he had passed the vicinity of the camp below and then work his way diagonally down the slope. As he took his first step downward he heard a voice softly calling his name.

      “Jimmie!” the voice said. “Hello, Jimmie.”

      Jimmie stopped and looked back. A figure was approaching him from the north, crouching down close to the slope of the rocks.

      “Carl!” he called. “Is that you?”

      “Sure!” was the reply. “I thought you had gone off in the machine.”

      “Then you went away and left her, did you?” demanded Jimmie.

      “Of course I did. I wanted to see what was going on!”

      “Did you see the people who took the machine away?” asked Jimmie.

      “I saw two figures—no faces,” was the reply.

      “Well,” Jimmie grunted, “we’ve got a nice little walk back to camp!”

      “I hope we don’t freeze to death on the way down,” Carl cut in.

      The boys walked steadily for a few moments, and then Jimmie stopped and regarded his companion with a questioning look.

      “Are you game?” he finally asked.

      “I’m game!” Carl answered. “We’ve lost the machine, and it doesn’t make any difference what happens now.”

      “That’s the way I look at it!” Jimmie returned.

      “What do you want to do?”

      “Now, look here,” Jimmie explained. “There’s only one person at the fire from which the signals were sent. He sits there like a wooden Indian, probably three-fourths asleep. The two men who went away on the Louise probably left the camp about the time we left the machine and went over the ridge to seize it. Now, suppose we go down there where that fellow sits alone and hold him up!”