Martinez exclaimed suddenly,
pointing a long thin forefinger at the mouth of the canyon where a
group of black dots were moving up the river.

"That's them," said the man who had given the warning.

"And they're armed," said another. "You can see the moon shine on
their gun-barrels."

On the opposite side of the stream, some two hundred yards below the
dam and three or four hundred feet lower in elevation than the camp,
advancing up the canyon in a string, the men looked like a line of
insects.

"I'm off for help," the doctor said, springing into his car. "Janet,
you and Mary go higher up among the rocks and hide if these buildings
are attacked." Away he went, buzzing down the hillside to the long
stretch of road.

Weir now came into sight, walking quickly towards the group. That he
saw the Mexicans down in the canyon was evident from his swift
appraising glances thither.

"Johnson, move your men down halfway to the dam and have them scatter
there behind bowlders. I shall go still lower down," he said. "You
will hold your fire until I signal with my hat from the dam."

"You're going to the dam?"

"Yes."

"We ought to go with you."

"I don't need you. You'll be more effective hidden above. You'll have
plenty of light as the moon is shining squarely in the gorge. And
await my signal."

"All right; you're the general."

"But take no extreme risks, Weir. The company doesn't ask you to
sacrifice yourself," Pollock stated.

"The sacrifice will be down among those fellows," Steele replied, with
set jaw. "Don't worry about me. Now, start, men."

He stood for a little watching the rate of progress of the line of
Mexicans ascending the stream, which was not rapid owing to the broken
rocks lining the bank. Then he swung about to the two girls.

"Every one here now is under my orders," he said. "You two will take
your car and go at once. This is no place for you."

"But----" Janet began.

"I'm taking no chances that you shall fall into the hands of those
scoundrels," he declared, sternly. "They may succeed in reaching this
spot. You must not be here; you must go."

Taking each by an arm he piloted them to the car.

"Sorry, but it has to be," he added. "This is work for men, and men
alone."

Janet and Mary climbed up into the seat.

"You--you will take care of yourself," Janet said, tremulously.

"I expect to. Still, this isn't going to be a croquet party; anything
may happen. Good-by."

With that h