down the mountain, looking for some secret entrance, but none was disclosed. The higher they went up the great peak, the fainter became he trail, until, at length it vanished completely.
But this was not to be wondered at, since it was on solid rock, in which no footsteps would leave an impression.
"They never brought you up here in a wagon, Mr. Jenks," decided Tom, when he saw how steep the place was.
"I'm inclined to think so myself," admitted the diamond man. "They must have reached the cave from some other way. As a matter of fact, I walked some distance after getting out of the vehicle, before we got to the cavern. But, even at that, I don't believe we came this way."
"Yet the phantom was here," persisted Tom, "and I'm convinced that the cave is in this neighborhood. It's up to us to find it!"
But they searched the remainder of that day in vain, and as night was coming on, they made their way back to the camp. As Tom, who was in the lead, approached the tent, he saw something black fastened to the entrance.
"Hello!" he cried. "Some one's been here. That wasn't on the tent when he left this morning."
