instant in rushing up the ladder and dropping over the side of the conning tower.

"Where's Matt?" cried Dick.

"That's just what I want to know," answered Speake, his consternation growing and a tremulous awe finding its way into his voice. "He was on the deck a few minutes ago, but he isn't here now. The last I saw of him he went aft, around the conning tower. The next thing I knew, when I turned and looked for him, he wasn't aboard."

All three of the lads were stricken dumb. For a brief space none of them spoke, but looked toward each other in the gloom, frantically alarmed and vaguely fearing—they knew not what.

"He couldn't have fallen overboard," spoke up Glennie, first to break the silence that held them as by an uncanny spell, "and yet it's certain he's not on the boat."

"Matt!" roared Dick, making a trumpet of his hands and calling into the blank darkness. "Ahoy, Matt!"

No answer was returned. All that could be heard was the hum of the submarine's motor, the swish of the propeller, and the lap and gurgle of waves along the rounded side.

Carl began to whimper.

"Ach, du lieber! Oof anyt'ing has habbened py dot bard oof mine, I don'd know vat I shall do, py shinks! He vas der pest friendt vat I efer hat, und——"

"Put about, Speake!" cried Dick, now thoroughly alive to the situation. "If Matt went overboard, then we're rushing away from him, and he's swimming somewhere in our wake."

The shaken helmsman immediately turned the Grampus in a wide circle and rang for full speed.

CHAPTER II.

HURLED INTO THE SEA.

Matt was very much worried when Dick and Carl, agreeably to their orders, went below. It was not the strange visitor that had passed the bows of the Grampus on its glowing way that rested heavily on his mind, but the news gathered from the captain of the mail boat that had been spoken early in the day.

On leaving the western end of the Strait of Magellan, the submarine and her crew had, as they supposed, left behind them for the rest of their cruise their wily enemies, the Sons of the Rising Sun. They had had trouble enough on account of the Japanese while coming through the strait, and Matt thought that he and his friends were entitled to a respite, so far as the nefarious plots of the fanatical young Japs were concerned.[A]

It was the responsibility for the safety of the Grampus that rested so heavily on the young motorist's mind. Weeks before, when the submarine had left Belize, British Honduras, Captain Nemo, Jr., the owner of the boat, had placed the craft entirely in Matt's hands.

"I wouldn't trust the Grampus with any one else, Matt," declared the captain. "But you've got nerve, your judgment is good, you know the craft from one end to the other, and whenever anything goes wrong and you get into a scrape, you've got a knack of always getting out of it without much damage to yourself. A hundred thousand dollars is to be paid for the Grampus when she reaches Mare Island. If the submarine doesn't reach there in good condition, the money will not be paid. Sickness will detain me for a while in Belize, and so that puts this work of taking the boat around the Horn up to you. Now go ahead!"

Motor Matt appreciated to the full Captain Nemo, Jr.'s trust and confidence. He had vowed to himself over and over again that he would prove to the captain he was worthy of the trust reposed in him. Matt was thinking of all this on the deck of the Grampus, after Dick and Carl had left him; and, in the midst of his reflection, he fancied he heard a muffled sound from somewhere in the submarine's wake.

Instantly alarmed, he passed the conning tower, without exchanging any words with Speake, and took up a position not far from the churning propeller. But he heard nothing further, and could see nothing either to increase or diminish his fears. He was just turning about to make his way forward, when a coil struck about his throat, drawing taut on the instant and preventing any outcry. At the same instant there came an irresistible pull backward.

Matt, astounded by this unexpected attack, reaching him from some point away from the boat and darting silently and suddenly out of the thick gloom, flung up his hands in an attempt to clutch one of the wire guys of the periscope mast.

He missed the guy by a fraction of an inch, slipped downward over the rounded deck and rolled into the water. He made little noise, so little that Speake could not hear it above the swirl of waves thrown up by the rounded plates of the Grampus.

Another moment and Matt was in the water and swimming. The deadly compression at his throat continued, and he was unable to voice a sound. He could see the little search light of the submarine moving rapidly onward into the darkness, and could see the half of Speake's form, like a blot of shadow, rearing out of the tower hatch.

All this time Matt felt the pull of the rope about his neck, drawing him steadily and remorselessly away into the foggy night. No one spoke behind him, and there was not the slightest sound to tell him who his captors were, or where they were, or how they had succeeded in making him a victim in that mysterious fashion.

A minute, two minutes, passed. At the end of that time Matt felt his strength leaving him because of the strangling grip about his throat. Then, suddenly, the rearward "pull" relaxed and the constriction at his throat ceased. With one hand he reached upward and pulled the strangling coil loose and gulped down a deep draught of air.

A moment later he gave vent to a cry, hoping to attract the attention of Speake. But the Grampus was too far away. With difficulty Matt freed himself of his shoes and coat. He had no idea how long he would have to swim, but he prepared himself to keep afloat as long as possible. What the end was to be he did not know, and he had no time to give to that phase of the question.

Some mysterious force had hurled him from the deck of the Grampus into the sea, and perhaps this same force would continue to take care of him. Turning about in the water, he lifted himself high with a downward stroke of his powerful arms, and peered in the direction from which the attack had come. He could see nothing and could hear nothing.

For a moment Motor Matt was tempted to forget his dire plight in marveling over the mysterious nature of that attack. The next instant, however, he began asking himself if it would be possible to reach the Chilian shore. It was a mile away, at least. To swim such a distance was no very extraordinary feat, but there were currents sucking Matt oceanward, and against these it was powerless for him to struggle.

Matt could keep afloat, but to what purpose? Would it be possible for him to keep on the surface until his friends on the submarine discovered his absence and put back to his rescue? Even if he could swim for that length of time, could his friends find him in that darkness, with the current dragging him farther and farther from the course over which the Grampus had recently passed?

In Motor Matt's place, a good many lads would have given up the struggle, but Matt was of different calibre. As long as there was a breath in his body he