At that moment, when all three were about to move toward the trail, they heard the report of a rifle. It sounded perhaps a quarter of a mile off, and directly to the south.
Now, there was nothing in this to cause any excitement on the part of the boys, but they looked in each other's faces with a half scared and half wondering expression, as though in doubt whether there was ground for fear or whether there was not.
"I believe that gun was fired by an Indian," said George in a whisper.
"How can you know that?" asked his brother, impatiently.
"I don't know it," answered the younger, "but I only think so."
"I don't know that it makes any difference to us whether it was an Indian or white man who fired it."
"Of course; and we can't know until we find out for ourselves," was the sensible but not altogether necessary remark of Master Jack.
CHAPTER XII.
THE STRANGE CAMP FIRE.
The young hunters now asked themselves whether it was worth while to try to find out who had fired the gun whose report broke in upon them with such startling suddenness.