the black
barren, thus marking it off as if it had been a mine. Before they went
to bed, Jack and Tom made another excursion to the upper end of the
island where they watched the campfires of the interlopers for some
time.

Suddenly, while they watched, they saw one of the boats with three
figures in it shoved off. The craft began to drop down the river.
Masterson, who was at the oars, steered straight for Rattlesnake
Island.

"They're going to land here," declared Jack.

"What do you think of that for nerve," gasped Tom.

"The worst of it is, we can't stop them."

"No, that's so. Let's hide behind this rock and see what they do."

The boys slipped behind a big boulder and a moment later the boat was
beached.

"Well, here we are," came in Eph's voice, "and if the stuff is worth
all you say it is, we ought to get enough out in a couple of nights to
make us rich."

"Gee! I can hardly wait till it's time to start digging," said Sam
Higgins. "Here we are, on Tom Tiddler's ground, picking up gold and
silver."

"Wait till we get it before you start hollering," said Masterson
gruffly.

"What time will we start over?" asked Sam.

"About midnight. It will be plenty of time."

"But how are we going to locate it?" objected Eph.

"We can see where they've been digging, can't we?" said Bill
Masterson, "or if they haven't started yet, we can hang around and
watch till they do."

The three worthies sat under a rock not far from where the boys were
and talked. It appeared that Bill Masterson had read up on mining and
claim law and knew that the boys could not order them off the island.
They had a right to take all of the mineral-bearing earth that they
could.

Suddenly, however, their talk stopped.

"What are you doing, Eph?" demanded Sam indignantly.

"Nothing. What do you mean?" asked Eph in an astonished voice.

"You threw a rock at me."

"I didn't."

"You did. Ouch! There's another."

"One hit me, too," cried Eph, springing up, and at the same moment a
yell came from Masterson.

Jack and Tom, as much surprised as the three marauders, heard the
rocks pelting around them. Suddenly they looked up. Standing on a high
rock above the place where Masterson and his cronies were talking, was
a strange-looking figure in tattered clothes outlined in the
moonlight.

He was busily hurling rocks down at the intruders. Suddenly a
demoniacal laugh split the air and the creature vanished, running
swiftly, crouched