A PRISONER—AND A SURPRISE.

Matt's shout acquainted the savages with the fact that there were two whites to be dealt with instead of one. The scoundrel in the canoe dropped his paddle and picked up a spear. The dugout dropped a little behind, but the savage brought the ungainly craft nearly to the conning tower with two sweeps of the paddle. The next moment he let his spear fly, and there came a blood-curdling whoop from the tower hatch.

Carl, as usual, happened to be in the way of trouble. He had flung through the periscope room and chased after Matt up the ladder. Matt avoided the spear by dropping to his knees. It passed over his head, snapped Carl's cap off his shock of tow-colored hair, and carried it on for a dozen feet, dropping out of sight with it beneath the water.

"Vat a vay iss dot!" bellowed Carl. "Tick, handt me oop a gun, or a gannon, or somet'ing. Matt, look oudt a leedle! Ach, himmelblitzen!"

Carl forgot the loss of his cap, forgot even that he had asked Dick for a weapon, and scrambled to get out of the tower and go to his chum's aid.

The savage who had been climbing up the rounded deck had made a spring for Glennie's back. Motor Matt leaped about the same time, grabbing the native before he could do the ensign any harm.

Matt, and the man he was holding, fell to the deck, rolled over the rounded plates, and splashed into the water.

"A rope!" howled Carl, jumping up and down on the deck to attract Dick's attention; "a rope! Matt iss in der vater mit a Inchun, und he vill be trowned!"

Dick came hurrying up the ladder with a coil of line.

"Here!" he cried, tossing the coil to Carl. "Get busy, mate. I'll lay the Grampus closer, and mind Matt gets hold of the rope."

Matt and the native were still struggling. The fact that they were in fifteen or twenty fathoms of water did not seem to impress either of them with the necessity of swimming to keep afloat.

When they first tumbled into the water, there was a great splash, and they disappeared; when they came up, they were puffing like porpoises, but Matt had his hands around his antagonist's throat, and the savage was hanging to Matt's hair.

"Help Glennie!" sputtered Matt, who, by then, was some distance astern. "Capture that man!"

"Glennie be hanged!" growled Dick. "We'll save our old raggie, no matter what happens to the blooming ensign."

Carl, standing ready to heave the rope, was mixed up in the ensign's battle by an unexpected trend of it which nearly knocked him overboard. The two, still twisting and striving for possession of the spear, struggled toward the conning tower and collided with the Dutch boy. The matter of self-defense suddenly presented itself to Carl, and he dropped the rope and went for the savage like a tiger.

It wasn't the spear Carl wanted, but the savage himself. The ensign was eliminated, and Carl and the native went down on the deck, rolling and pummeling.

"Ju-jutsu!" exclaimed the ensign, astounded at the science the untutored savage was showing. "Great Moses, he's using ju-jutsu and trying to break Pretzel's arm!"

"Save the arm, then!" snorted Dick. "Run that spear through the swab."

Glennie didn't impale the savage on the point of the spear, but he used the handle, and gave the arm that was bending Carl's a stout thump. A gasp escaped the savage's lips, and his arm dropped away as though paralyzed. Carl rolled over on top and got his fingers about his antagonist's throat.

"Gif me der rope!" he cried. "Misder Glennie, schust put a leedle piece oof der rope aboudt der feller's handts!"

Dick Ferral was not paying much attention to the fight Carl and Glennie were having. They were two to one, and there could not be much doubt as to the result of the contest. Dick's worry was reserved for Matt, for it seemed as though the savage in the water was bending every effort to drag Matt under and drown the two of them.

The other savage in the dugout was paddling like mad in an effort to get alongside the combatants. It had taken some time and space for the submarine to turn about on her course, and Dick was now driving her straight for the two in the water.

So far as Dick could see, both Matt and the savage were almost at the last gasp. How they ever kept afloat at all was a mystery.

As the boat shot in between the dugout and the pair in the water, the third savage could have thrown his spear to good effect—if he had had it. But he did not have it, and all he could do was to paddle off and furtively await the issue.

The submarine glided alongside Matt and the Indian, and Dick immediately made a discovery that took his breath.

The savage was yellow in spots—half yellow and half mahogany color.

"Here, Matt!" cried the voice of Glennie as he knelt on the deck while the submarine slowed in answer to Dick's signal. "Drop that fellow and catch this rope!"

"I can't drop him!" gurgled Matt.

Glennie reached over with the spear and tapped the savage on the head. Instantly the fellow, with a fierce snarl, let go of Matt and vanished under the hull of the Grampus.

Matt, thus left with his hands free, caught the rope and was dragged aboard. Glennie snaked him to the top of the deck, and, for a space, the young motorist lay there.

"Did you capture the other fellow?" asked Dick, as soon as he had rested a minute.

"He's tied to the other end of the rope that I used for pulling you in," replied Glennie.

"Good enough! Did you notice how that rascal I was fighting with changed color in the water?"

"Keelhaul me!" cried Dick. "I saw that! Was it war-paint he had on?"

"No war-paint about it, Dick," declared Matt. "There was a yellow skin under that brown paint."

"Und dis feller iss der same vay!" called Carl. "Look ad here, vonce!"

All eyes turned in the direction of the Dutch boy. He was sitting on his enemy's chest, holding him down, and there were dabs of brown pigment all over Carl's face. His hands were fairly coated with it.

"These savages have a yellow skin, Matt," said Glennie, "and it must be that they paint themselves a brown color when they go on the warpath."

"If what I have read is true," returned Matt, "there are no savage tribes at the mouth of the Amazon. All the Indians in these parts are at least half civilized."

"Then where did these rascals come from, and why have they attacked us in this venomous manner?"

"They came from that island where we cleared the propeller," said Matt.

"These are members of that gang?"

"Don't you recognize them, Glennie?"

"They all look alike to me. Of course, I suspected they were from the same tribe, but I didn't know they were the same men. There were five of them on the island."

"You wounded one of the others. Probably one of the fellows stayed behind to look after the wounded man's injury."

"But how could they get here in that dugout, and lay us aboard, like they did? We're a good ways from that island."

"No doubt, Dick," said Matt, "they surmized that we would take the South Channel on our way to Para. While we were meandering around in that blind passage they were paddling for this place, and getting ready to attack us."

"I like their nerve!" muttered Dick; "three of 'em tryin' to capture the Grampus!"

"You don't think they live on that island, do you?" asked Glennie.

"They live on an island, all right," returned Matt, "but it's a good many thousand miles from here."

Carl took a furtive look at Motor Matt.

"You vas joshing!" exclaimed Carl.

"If you fellows had your eyes," smiled Matt, "there wouldn't be any joshing."

"Some of that chink's dope is still fogging your brain, old ship," observed Dick. "But what's the use of talking? You've got your prisoner, Mr. Glennie. Better bring him downstairs. First thing you know he'll be in the water, and take Carl along with him."

"Nod me!" piped Carl. "Dere iss a rope aroundt his handts, und I'm holting him on der top oof der teck. Aber, I guess, ve might schust as vell dake him by der beriscope room."

"Look at him first," suggested Matt. "Glennie, you give him a close observation. I'm surprised at you fellows."

Glennie, Dick, and Carl were at a loss to know what Matt was driving at. Walking over to the prisoner the ensign bent down and stared at him.

"What!" he gasped, straightening up and peering excitedly at Matt. "Tolo!"

"Now you've struck it," laughed Matt. "Those supposed savages were merely a detachment of our old friends, the Japs. I discovered that as I dropped into the water. That's why I called out as I did. Here's our resourceful acquaintance, Tolo. First he's a Jap, next he's a Chinaman, and now he's a native of the Amazon. There's no telling what he'll be next time if we allow him to get away from us. Take him below, and let's have a talk with him."

Glennie and Carl, between them, succeeded in getting Tolo down the tower hatch. Before Matt went below he took a look behind. The dugout was far in the distance, with two men at the paddles.

From this evidence it was plain that Matt's antagonist had gained the canoe and was now, with his companion, paddling swiftly away to rejoin the rest of their friends.