e distance from the
viaduct, the boys glanced below. From the three broke a simultaneous low
cry of understanding and indignation.

In the light of several lanterns a party of seemingly fifteen or twenty
men were piling brush about the base of one of the central wooden piers.

"The K. & Z. people again, sure as you're born!" exclaimed Alex hotly.
"And after their solemn agreement!"

"If they succeed in burning it, they will hold back our supplies two or
three weeks, and reach the pass ahead of us, dead certain," added Jack
through his teeth. "We've got to stop them, boys!"

"Isn't there a hand-car or a velocipede here, Wilse?" Alex inquired.

"No. Not even a push-car. And it'd take one of us an hour and a half to
reach the construction-train."

"But that's certainly the only thing to be done," Jack pointed out.
"Perhaps two of us, with the rifles, could hold them--"

A flicker of light broke out below which was not a lantern, and
approached the dimly disclosed brush-pile. Quick as a flash Jack's rifle
went to his shoulder, and there was a reverberating crash. The light
disappeared and there came up a chorus of surprised shouts and the
clatter of running feet.

"Now we are in for it. I think we had better stick it out together," said
Alex quietly. "Perhaps the firing will be heard at the train."

The others agreed, and at Wilson's suggestion they made their way a few
feet down the slope to a ledge from which the whole structure of the
bridge could dimly be seen.

"How are you fellows off for ammunition?" whispered Wilson.

"I have four more rounds in the rifle, and thirty in my belt," said Jack.

"Five in the gun and twenty-seven in the belt," Alex announced.

Wilson had been examining the revolver and belt they had taken from the
prisoner, and which he had brought with him. "Fourteen in the two pistols
and nearly sixty in the two belts," he said.

"We ought to be able to put up all kinds of a fight," Alex declared
confidently. "That is, unless they--"

He broke off, and all leaned forward, peering down into the gloom, and
listening. From a little to the left rose the clatter of a pebble. Wilson
stretched himself on his face, and bent over, one of his pistols
extended. Barely breathing, they waited, and again came a faint clatter
as of loosened earth, nearer.

"Don't let him get too close," Alex whispered.

There came the sound of something snapping, a smothered exclamation, and
instantly Wilson fired