“I’ll bet you didn’t,” Jack muttered.

“What’s next?” Bob whispered.

But before the Indian could reply a sound broke the silence.

“What in the world was that?” Jack gasped.

“Listen,” Bob whispered.

Again the sound came to their ears. Beginning with a low rumble it grew louder until it ended in a piercing shriek.

“What is it, Kernertok?” Bob asked.

“Injun no know,” he replied.

“It’s only some more of their attempts to scare us,” Jack declared.

“And we don’t scare worth a cent,” Bob added.