The mule started off at a fast pace, keeping to the bottom of the valley and finally entering the canyon at the south end. Ned walked by Frank's side, his hand on the stirrup, listening for a sound he dreaded to hear. He was afraid one of the boys had been thrown from the animal's back, and might be lying, suffering, in one of the crevices or breaks which marked the bottom of the canyon.
After traveling some little distance in the canyon, Frank drew up and pointed ahead.
"Right over there," he said, "is the spot where we saw the smoke signs!"
"That's a fact!" Ned answered. "One of the boys must have come here to investigate and left Uncle Ike without tying! The mule has been here before, or he wouldn't plod along so steadily. Suppose we leave him here and walk on cautiously?"
"Just what I was about to propose," Frank agreed.
Uncle Ike seemed to resent being left alone in the canyon, which was now almost as light as day, save where the shadows of the mountain to the east lay along the wall on that side. The mule was finally quieted and left in a dark angle.
Moving in the shadows, the boys soon came to an angle in the cut and looked out on the remains of a campfire. They pushed on until they came opposite to it, but saw no one. In order to reach it they would be obliged to cross the canyon, not very wide there, but flooded with moonlight in the center.
While they stood in the shadow of the mountain a man came stumbling down the slope ten yards away from them. At first they thought it was one of their chums, but when the man's figure came into the moonlight they saw that he was tall, heavily built, and also heavily bearded. He walked straight across to the fire and passed it, turning into a shallow cave there was in the rock of the outcropping ridge.
The boys saw him enter the cave and look sharply around, then he disappeared as suddenly and completely as if he had walked into the solid rock.
"We're getting all the stage effects!" Frank whispered. "That man ducked into a moonshiner's establishment!"