conspiracy. Clear, too, it was that Burkhardt, determined
that no mistake or abandonment of the operation should occur, had come
to see it through in person. Weir could ask nothing better; he had one
of the plotters caught in the act.

Apparently orders had been to carry through the first part of the
diabolical plan of destruction in silence, that of gaining control of
the dam, for when two or three Mexicans flung up rifles to shoot at
Weir a sharp word from another Mexican, seemingly their leader, had
checked the volley and shouted to Burkhardt.

The latter had stopped; he stared for a few seconds at the man on the
white wall above and finally signaled with a wave of his arm.

"Come down here," he ordered.

But Weir made no move to obey. He continued to stand motionless,
coolly regarding the party beneath. His eyes particularly considered
two men who carried wooden boxes, square and stout, on their
shoulders. At last he spoke.

"What do you want here?"

"Come down, then you'll learn," Burkhardt shouted up, making no effort
to hide the enmity in his voice.

Weir puffed at his cigar, removed it from his lips to glance at its
glowing end, while the Mexicans stared up at him in silence, puzzled
by this lone guard who carried no rifle, who did not flee away to
spread an alarm and seek aid, and who so unexpectedly had appeared as
if anticipating their visit.

Murmurs broke out. Why were they not allowed to shoot him at once in
the approved Mexican bandit fashion and proceed to their work? If
he were not shot at once, he yet could escape for aid. The party
had to ascend the hillside in order to mount to the top of the
concrete work. Time would be required to place and fire their charges
of dynamite--and they were eager to get at the loot in the buildings
above.

"Kill him," Burkhardt roared suddenly, jerking forth his revolver and
blazing at the engineer.

The bullet sang past Weir's head. He did not duck; indeed, kept his
place calmly while the Mexicans were raising their guns, as if to show
his supreme contempt for their power. But at the instant Burkhardt
fired again and a dozen rifles blazed he sprang back and dropped flat,
leaving the deadly missiles to speed harmlessly above the dam.

Raising himself cautiously he seized the end of a fuse projecting from
one of the canisters and held the crimson end of his cigar against it
until a sputter of sparks showed that it had caught. From this fuse he
turned to t