As he worked, Slugger and Nappy approached until they were within plain sight of what he was doing. They did not make a sound, however, and Uncle Barney never suspected their presence.
When the flat stone had been set aside, there was revealed a small cache, lined with more stones. At the bottom of this cache rested a fair-sized tin box, dark blue in color, and secured with a padlock.
"Ha! I knew it was safe!" cried the old man in a relieved tone of voice. "I knew they couldn't find it!"
"Say! what do you suppose——" began Nappy, when Slugger clapped a hand over his mouth.
The low-spoken words echoed throughout the cavern, and, much startled, Uncle Barney dropped the tin box and sprang to his feet. As he did this Slugger Brown shoved his crony behind a projecting rock, and crouched low himself.
"Who is there?" cried the old lumberman, and caught up his gun. "Who is there, I say! Speak, or I'll fire!"
For reply, Slugger picked up a good-sized stone which was handy. Taking hasty aim, he hurled it at the old man. It struck Uncle Barney in the forehead, and slowly the old lumberman sank to the floor of the cave unconscious.