Ned could have danced with delight. The aeroplane appeared to be in perfect condition, but there was no one insight. Jimmie and Pedro must be about somewhere, the boy thought, as he considered the most practical way of reaching the valley, but where were they?

He was about to call out in the hope of arousing one of the aviators to action when he saw a hand waving at him from underneath the gray planes. A more careful inspection of the spot revealed the dirty face of little Jimmie, who was lying on his face, an automatic in each hand. Pedro was nowhere to be seen.

Ned watched the signaling hand for an instant and then, in response to what it said to him, scudded around the angle of rock by which he had reached the shelf. As he did so an arrow whizzed past his right ear and blunted against the rocky wall.

The situation was not difficult to understand. Jimmie had dropped the Nelson into the little valley and had there been attacked, either by savages or those interested in the defeat of the Boy Scout expedition to Paraguay, though how the latter could have reached that lonely spot so soon after the landing of the aeroplane was a mystery which the boy could not fathom.

Following the attack, Jimmie had hidden under the planes, and Pedro had probably taken to his heels. The situation explained, doubtless, why the boy had not returned with the airship. He had been held there by the enemies, virtually a prisoner.

After a short pause, during which Ned listened intently for some sound of pursuit, the boy moved cautiously to the shoulder of rock and looked around it to the shelf. There was no one in sight, so he pressed on, and once more came within view of the aeroplane.

Back of the planes he saw a head lifted from the lip of a gully which cut the valley like a trench. It was not the head of a savage, nor yet the head of a Peruvian mountaineer, for it was covered down to the eyebrows by a flat-topped leather automobile cap which was adorned with driving goggles! Evidently an American!

While Ned, himself unseen, watched the cap and the goggles, the wearer lifted himself and looked up over the edge of the gully. He wore a gray suit, tailor-made, from all appearances.

Back of him three ill-visaged Peruvian Indians also raised themselves to get a view of what was doing in front.

So the savages were led by an American! Instead of the automatic of civilized warfare, the enemy was resorting to the poisoned arrow of the barbarian!