"It is the wish of the president," was the reply.

"But what, why, when--"

"You have yet to see," was the impertinent reply. "You have yet to see if you can do these things to our countree!"

And so, mystified and, if the truth must be told, not a little discouraged, Ned was led through the prison corridors, his mind filled wit thoughts of Leroy, Jimmie, the Nelson, and, strangely enough, the Black Bear!

CHAPTER XV

THE WARNING FROM THE SKY

There was a shock when the prow of the Black Bear struck a canoe which lay full in its path. The momentum was r.e.t.a.r.ded for only a second. Then the motor boat was beyond the line of war canoes with their screaming, gesticulating occupants.

Looking out of the rear ventilator, Frank saw a smashed canoe running down with the current, with a dozen or more natives clinging to it. But there was still a large number of canoes up the river, and the Black Bear was struck more than once by forceless bullets and poisoned arrows as she sped past them.

Armed with modern rifles, the Indians would have made short work of the occupants of the Black Bear, but the muskets they used were old and mostly out of condition. The arrows were far more deadly, although they stood less chance of penetrating the tough panels.

"Now," Harry said, as they pa.s.sed a racing fleet of Indian boats, "we can open up a little and get a breath of fresh air! I'm just about suffocated!"

"Not just yet," Jack, who was at the front, said, "for there's a mess of the black scamps just ahead. They are on the bank, both banks, and seem to be waiting for something to happen. I wonder what it can be?"

"Some trap, I suppose," Harry gritted. "Well, all we can do is to ran on through them, if they come out in boats, and get out of their reach. We ought to be able to be out of this blasted country in a couple of hours."

"That's all right," Jack replied, "but you just listen a moment."

But the racing motors shut out all individual sounds, and Harry shut them down for a minute. Seeing this, Jack dropped an anchor at the prow, and the boat lay pulling at the cable in the current.

"What did you do that for?" asked Frank, addressing both boys from the stem.

"Listen!" commanded Jack.

"Look!" ordered Harry.

What Frank heard was the heavy, continuous roar of a waterfall.

What he saw, as he crowded up under the plate gla.s.s panel in the top, were the lights of an airship!

"I tell you," Harry cried, excitedly, "that that's the Nelson. You can't fool me about that."

"Why doesn't she come down, then?" demanded Jack.

"Because she doesn't know that this is the Black Bear. That is an easy one! If she did she'd be here in a second."

The boys studied the lights a moment and then turned their attention to the Indians, who were now making a great clamor. In a short time it was easy to see what they were up to.

Above roared the falls and the rapids. At this point in the Beni river there is a swift drop from the mountain plateau above. It will be remembered that the Beni reaches away up into the Illimani mountains, with its springs not far distant from the summit of the Andes.

Where the boys were the Paredon and the Paderneira, falls and the Araras and the Misericordia rapids made the navigation of the river, even in the protected Black Bear, impossible for many miles. The Indians seemed to understand this, for they had gathered at the foot of the falls, possibly expecting to see the craft attempt the ascent.

Jack watched them from the prow for a time and then asked:

"What's that they are throwing into the river?"

"Logs!" replied Harry, looking out over Jack's shoulder, "and brush!"

"Well, of all the--"

The sentence was not finished. Frank, at the stern, gave a yell and fired out of the loophole. "Come here!" he shouted, then, "if you want to see what the devils are doing. This takes the cake!"

A glance showed the others what the plot against them was. Harry went to his locker for his revolver and Jack drew his from a pocket.

"I guess it is a fight now!" Frank said. "You see what they are doing?"

"Of course. Anybody can see that."

Jack reached out of the opening and fired a perfect volley down stream. Frank crowded against him to look out.

"Never touched them!" he cried.

"No," Jack went on, "they're forming a bridge with their canoes and running logs and brush down against it. They've got an obstruction already that the Black Bear never can get through."

"What's the matter with dynamite?" asked Harry.

"Oh, we can use dynamite as long as we have it," was the reply, "but there will be Indians on guard there long after we are out of the stuff."

"I guess that's right!" with a sober drawing of the lips.

"I'll tell you what we've got to do," Harry said, presently. "We've got to put on full power and try to run up the rapids."

"Why, there is noise enough for a ten-foot fall," Frank replied.

"We've got to risk it," Jack went on.

"Now, you just wait," Frank cut in. "I don't think you've got this thing sized up right at all. Harry," he continued, "who does this boat belong to?"

"To the Black Bear Patrol," was the reply. "You know that well enough."

"Then we can do what we please with it, so long as we make it right with the other members of the Patrol?"

"Why, of course."

Jack looked at his chums with a grin.

"What are you figuring on?" he asked. "One would think you were planning to blow the Black Bear into smithereens."