and turning in the air, to fall with a thump on the back of his neck.

“Mah goodness!” he gurgled, as he lay on the ground, dazed by the shock of the fall. “De ol’ debbil done gib meh a boost then fo’ suah!”

The other lads looked at each other in perplexity.

“Well, wh-wh-what do you think of that?” stammered Rattleton.

“He ought to file his voice, whoever he is,” coolly observed Browning. “It’s a little rough along the edges.”

“It strikes me that somebody is having fun with us,” said Merriwell, a look of displeasure on his face.

“What are you going to do about it?” asked Harry.

“We don’t seem able to do much of anything now. Come on.”

Toots scrambled up, and they mounted their wheels. As they started to ride away, a hollow-sounding voice cried:

“Stop!”

“Oh, riv us a guest—I mean give us a rest!” flung back Rattleton.

“Stop!” repeated the mysterious voice. “Do not try the pass. There is danger beyond. Turn back.”

“I told you it was a warning!” cried Jack. “What do you think of it now?”

“I think somebody is trying to have a lot of sport with us!” exclaimed Frank.

“Well, what are you going to do?”

“Not a thing. I don’t propose to pay any attention to it, Come on, fellows. We must have more water, and there’s none too much time to find it before dark.”

Diamond was tempted to declare he would not go any further, but he knew the others would stand by Frank, and so he pedaled along.

As they drew away from the spot where they had seen the skeleton, they heard the mysterious voice calling to them again, commanding them to stop and turn back. Thus it continued till they had ridden on so that it could be heard no longer.

Despite himself Frank had been impressed by what he had seen and heard, and a feeling of awe was on him. Ahead the shadows were thick where the dark cliffs seemed to come together, and there was something grim and overpowering about the bare and towering mountains that sullenly frowned down upon the little party.

The boys were silent, for they had no words to speak. Each was busy with his thoughts, and those thoughts were not of the most pleasant character.