"That is uncertain. I may return by night, and I may not be back for several days."
The foreman looked as if he wished to ask where Frank thought of going, but held himself in check.
"I wish to satisfy myself if any of my enemies are in this vicinity," said Merriwell. "I leave things in your hands here, and I believe I can trust you."
"You can, sir, fully."
Merry attended to the saddling of his horse. When he rode forth from the mine he was well armed and prepared for almost anything. Behind him the roar of the ore-crushers died out, and he passed into the silence of the mountains.
Not an hour had passed when he was somewhat surprised to see before him from an elevated point a big, ball-like cloud of dark smoke rising into the sky.
"That's odd," was his immediate decision.
He stopped his horse and watched the smoke as it ascended and grew thinner. It was followed by another ball of smoke as he watched, and after this came still another.
Then Frank turned in the saddle, looking in various directions. Some miles behind him three distinct and separate clouds of smoke seemed to be mounting into the sky from another high elevation.