Jack was the first to speak.

"Fix the fire so you can leave it for a short time if necessary, Plum."

"Leave it any time, Jack. I wasn't so green firing as they thought me.

Reckon my firing Joe Staples' old saw-mill didn't hurt me any for this business."

"Did you burn it down, Plum, or was it sav--"

"Scat! you know what I mean. But do yeou begin to see anything ahead?"

"I could hardly expect to so soon, for they will be pretty sure to keep out of sight until we are into their trap."

"Do yeou think they will have a rock on the track?"

"Perhaps some obstruction. I can't just imagine how they will take us this time."

"Say, Jack, what do yeou think of 'em fellers on the train?"

The words seemed so much like an echo of his own thoughts that the boy engineer started with surprise at the question.

"I'll bet yeou," continued Plum, "they'll make us more trouble than the fellers in the bushes."

"Plum Plucky, you just speak my mind. I was thinking how we could best get rid of them."

"Bully for yeou, Jack North! Tell me what to do and I'm with yeou tooth and nail."

"In one respect we are fortunate," said Jack, in a tone which showed that he had been pondering carefully over the matter. "The car they are in is to the extreme rear."

"You intend to take the freight through if possible?"

"At any cost."

"Well, then, what does their being in the rear car have to do with our getting the rest through? Looks so they air fixed to help the raiders best so."

"Why simply--look yonder!" said Jack, pointing suddenly a little to their right in the distance ahead.

Plum Plucky did as he was told.

"What is it, Jack, a big rock?"

"Rock? No! Look over those tree-tops; don't you see that thin column of smoke rising high into the air and as straight as a church spire?"

"Gosh! yes. What of it? There can't be much wind."

"It is a signal of the bush-raiders."

"S'pose it is?"

The train was now winding through the valley of the Rio Tasma, and the sullen roar of the mountain stream was beginning to be heard above the thunder of the cars, which were rushing along at a rapid rate.

"I am sure of it," replied Jack, as he continued to watch the ascending smoke, though without neglecting his survey ahead. "What else can it mean?"

"Sure enough."

"Do you think we have a brakeman we can count on in case of an attack?"

Plum hesitated a moment before replying.

"Not unless it is little Pedro."

"Just my mind. See! the smoke is dying out. Whatever message they had to make has been made."

"What do you think it could be?"

"I will tell you what I think. Just before that column appeared we must have been in sight of whoever was on that height, and they gave that as a signal that we were coming."

"Jack you are n.o.body's fool; but couldn't they hear the sound of the train?"

"Not above the roar of the river if they are on the other side."

"I didn't think of that. But what about little Pedro?"

"Only this: In case those chaps in the rear car show signs of being against us we must get rid of them as soon as possible. Do you think you can go back to Pedro?"

"Yes."

"Well, do so at once and return as soon as you can, for every moment is precious now. Tell Pedro the moment he hears the bell ring to uncouple the rear car. Mind you, only that. He must be there ready at all times until we have pa.s.sed through the woods. Get back as soon as you can."

"You can count on that," and with these words Plum began to climb over the tender toward the line of cars behind.

The bridge of the Rio Tasma was now in plain sight, and Jack's whole attention was fixed upon the new structure that spanned the rapid stream.

Everything seemed all right there, so he allowed the train to rush on at unabated speed.

There was a wild fascination about this perilous trip that Jack could not shake off. Every moment he expected to run into some unknown danger, and he would not have been surprised to find the bridge suddenly collapsing beneath the train.

But nothing of the kind occurred, and the engine was speedily across the stream.

He was approaching the place where he had so narrowly escaped death from the falling bowlder, and he could not help glancing toward the top of the cliff, as he was carried around the curve.

At that moment the report of a gun rang out sharply on the air, the sound coming from the rear of the train.

Then an answering report came from the depths of the forest ahead!

"The men in the car are signaling to the raiders!" flashed through Jack's mind, and, simultaneously with the thought, he gave the bell cord a quick jerk.

"If Plum has only got there," he thought, as he turned his gaze upon the course ahead.

He knew that Plum nor Pedro could not uncouple the car as long as they were climbing the upgrade, but immediately beyond the bend a descent was made into the valley.