"Well," the lieutenant responded, "if you had traced its course you would have seen that it is swung from this mountain to the one directly to the south, just at the point where the valley between narrows down to little more than a deep ravine." "But it doesn't run into our lines," Frank objected again. "That's true," Lieutenant Mackinson admitted again, "but it may serve our purposes just the same." "How?" Slim asked entreatingly. "Tell us what your plan is, Lieutenant." "No," replied the young officer in teasing tones, "I don't want to raise your hopes until I determine whether it can be accomplished." And he plodded on toward the tractor, refusing to answer another question. Indeed, it is doubtful if he heard them, for he was busy with some important mental calculations--problems that required his engineering knowledge and ability, and that had directly to do with the personal safety of every man in the party. "What tools have we here?" he asked of Frank Hoskins, as they arrived at the wrecked wireless tractor. Frank opened up a tool chest that showed a great variety of implements in almost every size and shape. "Good," said the lieutenant, as he looked up from where he was rummaging in another part of the car. "Here, Jerry," he commanded, "let me have that mallet and cold chisel and then help me rip a couple of these boards off the floor." He had laid aside a large pulley wheel, several nuts and bolts and some heavy copper wire. With the aid of the mystified Jerry he tore two stout boards up from the floor of the tractor. "Now we've got to work rapidly, fellows," he said, "for it will soon be dark, and we don't want to attract attention to ourselves by making a light. "Here is what I am going to try to do: That wire is strung really from mountain to mountain, running down a slight grade from where it is fastened here to where it is tied up over there. I don't know how strong it is, or how securely it is fastened at the other end, but I'm going to find out. "You've all seen those trolley-like boxes that run on wires in department stores, with which the clerk sends your money to the cashier's desk, and the cashier returns the change? Well, I'm going to construct something on the same principle, only I want to make it strong enough to carry my weight. "If I can do that, and the wire holds, the incline is sufficient to carry a passenger to the other mountain without any propelling power. I'll try it first, and carry with me one end of this reel of copper wire. If I get over all right I'll attach the wire to the little oar and you fellows can haul it back for the next passenger, and so on until all of us are over." Slim looked dubious. "How thick is that wire?" he demanded anxiously. "You know Slim's a trifle heavy," Jerry reminded the lieutenant. "Well," said Slim in a serious tone, "I'd rather fall into the hands of the Germans, and have some chance for my life, than spatter myself all over the bottom of that ravine."