He looked at the map again. They had followed the directions exactly, and if the map was correct they should find a tunnel leading from the rocky chamber in which they stood.
"Listen!" said Joe suddenly.
They stood stock-still, not saying a word. The silence of the mine was profound.
"What's the matter?" whispered Frank finally.
"I thought I heard a sound—like some one talking."
They listened again, but they could hear nothing save the occasional drip-drip of water from the walls.
"It must have been my imagination," said Joe, at last. "But I was sure I heard a voice."
"This mine is full of echoes. It was probably only the wind whistling down the shaft."
"I guess that was it. But this place is so creepy a fellow imagines almost anything."
"It would be a tough break for us if the outlaws marched in on us just now."