“Is anything wrong?” inquired the president.  He was answered by more explosions in the distance.

“I’m afraid so,” Tom muttered, showing his first trace of uneasiness.  “However, I don’t want to say, Mr. Newnham, until I’ve investigated.”

Before the horses were ready Tom descried, half a mile away, on a clear bit of trail, a horseman riding in at a furious gallop.

“There comes a messenger, Mr. Newnham,” Tom went on.  “We’ll soon know just what the trouble is.”

“Trouble?” echoed Mr. Newnham, in astonishment.  “Then you believe that is the word, do you?”

“I’m afraid, Mr. Newnham, that you’ve reached here just in time to see some very real trouble,” was Reade’s quick answer.  “But wait just two minutes, sir, and we’ll have exact information.  Guessing won’t do any good.”

Once or twice, through the trees, they caught sight of the on-rushing rider.  Then Jack Rutter, a big splotch of red on the left sleeve of his shirt, rode hard into camp.

“Reade,” he shouted, “we’re ambushed!  Hidden scoundrels have been firing on us.”

“You’ve ordered all the men in?” called Tom, as Rutter reined up beside him.

“Every man of them,” returned Jack.  “Poor Reynolds, of the student party, is rather seriously hit, I’m afraid.  Some of the fellows are bringing him in.”

“You’re hit yourself,” Tom remarked.

“What?  That little scratch?” demanded Rutter scornfully.  “Don’t count me as a wounded man, Reade.  There are some firearms in this camp.  I want to get the men armed, as far as the weapons will go, and then I want to go back and smoke out the miserable rascals!”

“It won’t be wise, Jack,” Tom continued coolly.  “You’ll find that there are too many of the enemy.  Besides, you won’t have to fatigue yourselves by going back over the trail.  The scoundrels will be here, before long.  They doubtless intend to wipe out the camp.”

“Assassins coming to wipe out the camp?” almost exploded President Newnham.  “Reade, this is most extraordinary!”

“It is—–­very,” Tom assented dryly.

“But who can the villains be?”

“A picked-up gang of gun-fighters, sent here to blow this camp off the face of the earth, since that is the only way that the backers of the rival road can find to set us back,” Tom rejoined.  “If they drive us away from here, they’ll attack the construction force next!”

CHAPTER XVI

SHUT OFF FROM THE WORLD

Five horsemen belonging to the field party rode in furiously, Matt Rice at their head.

“It’s a shame,” yelled Rice, as he threw himself from his horse.  “I’d have stayed behind—–­so would the others—–­if we had had rifles with us.  The scoundrels kept up a fire at a quarter of a mile range.  Then we passed the men who are carrying Reynolds—–­they’re almost here now—–­but it wouldn’t have done any good for us to stand by them.  We’d have made the other party only a bigger mark.  Where are the revolvers, Reader?  We’ve got to make a stand here.  We can’t run away and leave our camp to fall into their hands.”