ed whimsically and assented. He could keep quiet when he had
to; but the day following found him again restlessly investigating
anything that seemed worth the trouble and the afternoon saw him
standing looking upward toward the same valley of dread.

"I've got over it a little," he said to the younger man, "and do you
know I'm right curious to go over there and see how big that rock was
that tumbled into the mouth of the old shaft. Want to come along?"

Dick had sustained that same curiosity, so together they made their
way to the beginning of the previous day's disaster. They chilled when
they saw how effectually they had been caught; for the bowlder
completely filled the entrance to the shaft and would have proved a
hopeless trap had they tried to escape by burrowing around its edge.
It rested, as they had discovered, on solid rock, and its course down
the hillside was clearly marked.

"What gets me," said the veteran miner, "is what could have started
it. I noticed it up there when we went in. It was sort of poised on
that little ledge you see, and it didn't have to roll more than thirty
feet."

He began to climb up the bowlder's well-defined path, and suddenly
called to his partner with a hoarse shout, needlessly loud.

"Come up here," he said. "That bowlder never started itself! Some one
helped it. What do you think of that?"

Dick hastily climbed up to his side and looked. The rock around was
bare of growth or covering, so that no footprints could be discerned;
but a rock rested there that had plainly been used as a fulcrum. The
surface beneath it was weather beaten and devoid of moisture, which
indicated that it had lain there but a short time, probably only from
the time of its mission on the preceding day. They found themselves
standing up and staring around at the surrounding hills as if seeking
sight of the man who had attempted to murder them.

"We'll find out about this!" Bill exclaimed. "Good thing we know
enough to look."

He limped to the edge of the barren spot and began to circle around
its edge, while Dick did likewise, following his example. They found a
footprint at last and took the trail. It did not lead them far before
they came to a path on top of the hill that was so well used that any
attempt to follow it was useless; but, intent on seeing where it led,
they walked along it as it led straight away toward the timber.
Scarcely inside the cool shadows of the tamaracks they paused and
lo