The earth was a better conductor of sound than the atmosphere, which accounted for what at first seemed curious.
The boy applied his ear as before, and again he heard the noise, faintly, but distinctly; As the eye was of no use, he pressed his head against the blanket and listened.

Several minutes were occupied in this manner, and then he said, in an undertone: "I know what it is!--it is somebody walking as softly as he can.

There is another way of getting into this cavern, and those Apaches have found it out.

They've got inside and are hunting for us!".