“What do you make of the weather, Nat?”

Joe Hartley turned to Nat Trevor as he spoke, and scanned the face of the young leader of the adventure-seeking Motor Rangers with some anxiety.

But the stout and placid Joe’s unwonted look of apprehension found no reflection on the firm countenance of Nat Trevor, who stood as steadily at the wheel of the Nomad as if that sixty-foot, gasolene-driven craft was not, to use Joe’s phrase of a few moments before, pitching and tumbling “like a bucking broncho.”

“It does look pretty ugly for a fact, Joe,” rejoined Nat, after he had scrutinized the horizon on every side.

“And this is a part of the Pacific where we were warned before we left the Marquesas that we must look out for squalls,” returned Joe, still looking worried.

“Oh, well, the Nomad has weathered many a good hard blow, not to mention those waterspouts,” commented Nat. “I guess she’ll last through whatever is to come.”

At this moment a third boyish countenance was suddenly protruded from a hatchway leading to the Nomad’s engine-room.

“S-s-s-s-say, y-y-y-you chaps,” sputtered our old acquaintance, William—otherwise and more frequently Ding-Dong—Bell, “w-w-what’s in the w-w-w-wind?”

“A bit of a storm, I guess, Ding-Dong,” returned Nat, watching his steering carefully, so as to send the Nomad sliding easily over the long, oily swells, “but don’t you mind, old chap. She’ll stand it, never fear. How are your engines running?”

“L-l-l-like a d-d-d-dollar w-w-watch,” returned Ding-dong, with a note of pride in his tones.

“Good. Now if only we were farther to seaward of that island yonder, I’d feel easier,” commented Nat.

“Say, Nat,” struck in Joe, as Ding-dong dived below once more, “it seems to me we are a long time passing that island.”

“I agree with you, Joe. That is what made me ask Ding-dong about his engines. At the pace they are turning up, we should have left it behind us long ago, yet there it is, still on our starboard bow.”

“And we are getting closer in to it all the time, you’ll notice,” rejoined Joe.

“There must be some powerful currents hereabouts,” said Nat, looking for the first time a little bit troubled. “There’s something queer about that island, anyhow. I can’t find it on the chart. According to that, this part of the mid-south Pacific is absolutely free from islands or rocks.”

“Hullo,” cried Joe suddenly, “that’s odd! Look, Nat, the island isn’t really one island at all. It’s two of them.”

This paradoxical speech was really a correct explanation of the case, as it now appeared. The Nomad had, by this time, made some little progress over the rising sea, and as the bit of land “opened out,” it could be seen that there were, as Joe had said, two islands, with a narrow channel running in between them.

“Phew!” whistled Nat. “This complicates the situation. To make matters worse——” He stopped short.

“Well?” demanded Joe.

“Never mind,” replied Nat; and then in an undertone he added to himself: “I may be wrong, but I’ll bet the hole out of a doughnut that we are being dragged round toward that passage.”

That such was actually the case, he realized to his dismay an instant later. Head the Nomad’s bow round as he would, some invisible force still dragged her in toward the two islands. It soon became apparent, too, that the narrow channel was, in reality, more in the nature of a cleft between the two masses of land. Its walls were steep and sheer and formed of grayish rock. It could now be seen that the water in this abyss was boiling and bubbling as if in a caldron.

Nat and Joe exchanged glances of dismay. It was no longer possible to disguise the fact that they were momentarily being sucked, as though by invisible yet resistless forces, toward this ominous looking chasm.

The three youths had set out for the California coast, on which was their home, some days before, from the Marquesas group of islands, where they had had some surprising adventures. What these were will be found set down in the third volume of this series, “The Motor Rangers on Blue Water.” It may be said here, briefly, that their experiences in the South Seas had included the routing of a rascally band, who had made a headquarters on one of the Marquesas Group, and the discovering of the rightful owner of some valuable sapphires which had come into their possession in a truly remarkable way.

Of how they acquired these sapphires, and of the adventures and perils through which they passed before they gained full possession, details will be found in the second volume of the Motor Ranger Series, namely, “The Motor Rangers Through the Sierras.” In that volume, we followed our youthful and enterprising heroes through the great Sierra range, and learned of their clever flouting of the schemes of the same band of rascals whom they re-encountered in the South Seas. Among other feats, they located and caused the destruction of the hitherto secret fortress of Colonel Morello, a notorious outlaw. This earned them his undying enmity, which he was not slow to display. In this volume, too, it was related how the lads found, in a miner’s abandoned hut, the wonderful sapphires.

It now remains, only briefly, to sketch the earlier experiences of the three lads, to give our readers a grasp of their characters. In the first volume of this series, then, which was called “The Motor Rangers’ Lost Mine,” the three lads set out for Lower California on a mission which was to involve them in unlooked-for complications.

This errand grew out of Nat’s employment as automobile expert by Mr. Montagu Pomery, the “Lumber King,” as the papers called him, who made his winter home at Santa Barbara. Nat, who lived with his mother, was, at that time, very poor, and much depended on his situation with the millionaire, in charge of his several cars. But Ed Dayton, who considered that Nat had superseded him in the place, made trouble for him. Aided by Donald Pomery, the lumber king’s son, a weak, unprincipled youth, he hatched up a plot, which, for a time, put Nat under a cloud. But Mr. Pomery himself proved Nat’s firm friend.

Owing to Mrs. Pomery’s interference, the millionaire was compelled to discharge Nat, but he almost immediately re-employed him on the confidential mission of which we have spoken. This was to visit Lower California and investigate conditions on his timber claims there. Much rare and valuable wood had been going astray, and Mr. Pomery suspected his superintendent, Diego Velasco. He lacked proof, however, and Nat he selected as a bright, trustworthy lad, who could carry out an investigation painstakingly.

Nat recalled that his dead father had been interested, in his youth, in a rich mine in Lower California, and the prospect of the trip, therefore, had a double fascination for him. Mr. Pomery provided an automobile, equipped in elaborate fashion, for the long trip, much of which was to be made through desert country. With Mr. Pomery’s permission, Nat invited his two chums, Joe Hartley, son of a well-to-do department store keeper, and William Bell, the stammering lad, to accompany him. The latter’s mother and the former’s father at first demurred considerably to the trip, but at last they gave their consent. Nat, for his part, had some trouble winning his mother over. But soon all was arranged, and they set out. How they discovered the Lost Mine, and Nat became rich, was all told in that book, together with many other adventures that befell them. The reader is now in a position to understand our chief characters, sturdy, intelligent Nat Trevor, with his curly black hair and dancing blue eyes; stout, red-faced Joe Hartley, always good-natured, though inclined to be a bit nervous, and Ding-dong Bell, the cheery, stuttering lad, whose eccentricities of speech provided much amusement for his companions.

The day on which this story opens was the seventh since their departure from the Marquesas on their return voyage to the Pacific Coast. They had left behind them their fellow adventurers, some of whom wished to return by steamer, while others were anxious to continue their travels in the fascinating South Seas. So far, smiling skies and sunny seas had been encountered. But this particular day had dawned with a smoky, red horizon, through which the rising sun blazed like a red-hot copper ball.

It had been oppressively hot—torrid, in fact. But although the air was motionless and heavy, the sea was far from being calm. It heaved with a swell that tossed the Nomad almost on her beam-ends at times. That some peculiar kind of tropical storm, or typhoon, was approaching, Nat felt small doubt. A glance at the barometer showed that that instrument had fallen with incredible rapidity. A candle, held in the thick, murky air, would have flamed straight skyward without a flicker.

Dinner was eaten without a change being observable in the weather conditions, and, on coming on deck to relieve Joe at the wheel while he went below to eat, Nat sighted the bit of land toward which they were now being drawn like a needle to a lodestone. In the meantime the weather had been growing more and more extraordinary. The copperish sky had deepened in color till a panoply of angry purple overspread the heaving sea. The sun glared weakly through the cloud curtains as through a fog. But still there had come no wind.

Hardly had the two lads on the bridge of the Nomad realized that they were inexorably being drawn toward the two islands, however, when from far off to the southwest there came a low, moaning sound. It seemed almost animal in character; like the lowing of an angry bull, in fact, was the comparison that occurred to Nat. The sound increased in violence momentarily, while the sky from purple changed to black, and a blast like that from an open oven door fanned their faces. Through this awe-inspiring twilight the Nomad continued her inexplicable advance toward the two islands.

“Here it comes!” shouted Joe suddenly, as, from the same quarter as that from which the wind had proceeded, there came a sudden, angry roar.

“Hold tight for your life!” flung back Nat over his shoulder, gripping his steering wheel with every ounce of strength he possessed.

And thus began hours of stress and turmoil, which the Motor Rangers were ever to remember as one of the most soul-racking experiences of their young lives.