"That we can get out of the cave?"
"Exactly. See, here is an old coat and a pair of old shoes. Somebody has been in the habit of coming here—and he wasn't in the habit of getting in the way we got in."
They moved on, and soon reached a larger opening. Here they found a bit of old harness and, further on, where the ground was soft, the tracks of wagon wheels.
"Somebody has been in the habit of driving right in here!" exclaimed Tom. "We are sure to get out!" and his face showed his relief.
"Hark! what's that?" cried Sam, and shrank back as a strange rumbling was heard. "Is it an earthquake, or a landslide?"
"It's thunder, that's all," said Dick, a minute later, as they listened.
"To be sure—the storm was on us when we fell into the first hole," answered the youngest Rover.
"Perhaps we can be glad we are under shelter—if the storm is going to be a bad one," came from Tom. "But, come on, I want to see daylight again."
He moved on and then gave a cry of astonishment.
"Look!"