Just then Del Mar's boat ran around the promontory where Wu Fang had met the submarine that had brought Del Mar into the country and landed him so strangely.

The boat slowed down under shelter of the rocks and Del Mar added a pair of heavy lead-soled shoes to his outfit in order to weight himself down. Finally he put on the helmet, let himself over the side of the boat, and disappeared into the water.

His aide started the motor and the boat shot ahead again, with the dummy still occupying Del Mar's seat. As the boat swung out and made a wide sweeping curve away from the point at which Del Mar had gone overboard, the naturalist in the Dodge boat came around the promontory and saw it, changing his course accordingly, and gaining somewhat.

Del Mar sank, upright and rapidly, down in the shallow water to the bottom. Once having his feet on something approaching firm ground, he gazed about through the window-like eye of the helmet until he got his bearings. Then he began to walk heavily along the bottom of the harbor, over sand and rocks.

It was a strange walk that he took, half stumbling, slowly and c.u.mbersomely groping his way like a queer under-water animal.

If any one could have seen him, he would have noted that Del Mar was going toward the base of a huge rocky cliff that jutted far out into the harbor, where the water was deep, a dangerous point, avoided by craft of all kinds. Far over his head the waves beat on the rocks angrily. But down there, concealed beneath the surface of the harbor, was a sort of huge arch of stone, through which a comparatively rapid current ran as the tide ebbed and flowed.

Del Mar let himself be carried along with the current which was now running in and thus with comparative ease made his way, still groping, through the arch. Once under it and a few feet beyond, he deliberately kicked off the leaden-soled shoes and, thus lightened, rose rapidly to the surface of the water.

As he bobbed up, a strange sight met his eyes--not strange however, to Del Mar. Above, the rocks formed a huge dome over the water which the tides forced in and out through the secret entrance through which he came. No other entrance, apparently, except that from the waters of the harbor led to this peculiar den.

Lying quietly moored to the rocky piers lay three submarine boats.

Further back, on a ledge of rocks, blasted out, stood a little building, a sort of office or headquarters. Near-by was a shed where were kept gas and oil, supplies and ammunition, in fact everything that a submarine might need.

This was the reason for Del Mar's presence in the neighborhood. It was the secret submarine harbor of the foreign agents who were operating in America!

Already a sentry, pacing up and down, had seen the bubbles in the water that indicated that some one had come through the archway and was down "below," as Del Mar and his men called it.

Gazing down the sentry saw the queer helmeted figure float up from the bottom of the pool. He reached out and helped the figure clamber up out of the water to the ledge on which he stood. Del Mar saluted, and the sentry returned the secret salute, helping him remove the dripping helmet and suit.

A moment later, in the queer little submarine office, Del Mar had evidently planned to take up the nefarious secret work on which he was engaged. Several men of a naval and military bearing were seated about a table, already, studying maps and plans and doc.u.ments of all descriptions. They did not seem to belong to any nation in particular.

In fact their uniforms, if such they might be called, were of a character to disguise their nationality. But that they were hostile to the country under which they literally had their hidden retreat, of that there could be no doubt.

How high Del Mar stood in their counsels could have been seen at a glance from the instant deference exhibited at the mere mention of his name by the sentry who entered with the submarine suit while Del Mar got himself together after his remarkable trip.

The men at the council table rose and saluted as Del Mar himself entered. He returned the salute and quietly made his way to the head of the table where he took a seat, naturally.

"This is the area in which we must work first of all," he began, drawing toward him a book and opening it. "And we must strike quickly, for if they heed the advice in this book, it may be too late for us to take advantage of their foolish unpreparedness."

It was a book ent.i.tled "Defenseless America", written by a great American inventor, Hudson Maxim.

Del Mar turned the pages until he came to and pointed out a map. The others gathered about him, leaning forward eagerly as he talked to them. There, on the map, with a radius of some one hundred and seventy miles, was drawn a big segment of a circle, with Peekskill, New York, as a centre.

"That is the heart of America," said Del Mar, earnestly. "It embraces New York, Boston, Philadelphia. But that is not the point. Here are the great majority of the gun and armor factories, the powder and cartridge works, together with the princ.i.p.al coal fields of Pennsylvania."

He brought his fist down decisively on the table. "If we hold this section," he declared, "we practically hold America!"

Eagerly the other emissaries listened as Del Mar laid before them the detailed facts which he was collecting, the greater mission than the mere capture of Kennedy's wireless torpedo which had brought him into the country. Detail after detail of their plans they discussed as they worked out the gigantic scheme.

It was a war council of a secret advance guard of the enemies of America!

Meanwhile, Del Mar's man in his boat, cutting a wide circle and avoiding the Dodge boat carrying the naturalist, made his way across the harbor until he came to the sh.o.r.e.

There he landed and proceeded up the beach to the foot of a rocky cliff, where he turned and followed a trail up it to the top. It was the same path already travelled by my captors with me and later followed by Elaine.

As he came stealthily out from under cover, Del Mar's man gazed down the stairway. He drew back at what he saw. Slowly he pulled a gun from his pocket, watching down the steps with tense interest. There he could see Elaine and myself wearily climbing toward the top, our backs toward him, as we covered the men in the cave.

So surprised was he at what he saw that he forgot that his boat below had been followed by the mysterious naturalist, who, the moment Del Mar's man had landed, put on the last burst of speed and ran the Dodge boat close to the spot where the aide had left Del Mar's.

A glance into the boat sufficed to tell the naturalist that the figure in it was only a dummy. He did not pause, but followed the trail up the hill, until he was close after the emissary ahead, going more slowly.

Only a few feet further along the cliff, the naturalist paused, too, keeping well under cover, for the man was now just ahead of him. He looked fixedly at him and saw him gaze down the cliff. Then he saw him slowly draw a gun.

Who could be below? Quickly the naturalist's mind seemed to work. He crouched down, as if ready to spring.

The emissary slowly raised his revolver and took careful aim at the backs of Elaine and myself, as we came up the steps.

But before he could pull the trigger, the naturalist, more like one of the wild animals which he studied than like a human being, sprang from his concealment in the bushes and pounced on the man from behind, seizing him firmly.

Over and over they rolled, struggling almost to the brink of the precipice.

Elaine and I had got almost to the top of the flight of steps, when suddenly we heard a shout above us and sounds of a terrific struggle.

We turned, to see two men, neither of whom we knew, fighting. One seemed to be a professor of natural history from his dress and general appearance. The other had a sinister nondescript look.

Nearer and nearer the edge of the cliff they rolled. We crouched closer to the rocky wall, gazing up at the death grapple of the two. Who they were we did not know but that one was fighting for and the other against us we could readily see.

The more vicious of the two seemed to be forcing the naturalist slowly back, when, with a superhuman effort, the naturalist braced himself.

His foot was actually on a small ledge of rock directly at the edge of the cliff.

He swung around quickly and struck the other man. The vicious looking man pitched headlong over the cliff.

We shrank back closer to the rock as the man hurtled through the air only a few feet from us. Down below, we could hear him land with a sickening thud.

Far over the edge Elaine leaned in a sort of fascination at the awful sight. For a moment, I thought the very imp of the perverse had got possession of her and that she herself would fall over. She brushed her hand unsteadily over her eyes and staggered. I caught her just in time.

It was only an instant before the brave girl recovered control of herself. Then, together, we started again to climb up.

As we did so the naturalist looked down and caught sight of us approaching. Hastily he hid in the bushes. We reached the top of the stairway and gazed about for the victor in the contest. To our surprise he was gone.

"Come," I urged. "We had better get away, quickly."

As Elaine and I disappeared, the naturalist slowly emerged again from the bushes and looked after us. Then he gave a hasty glance over the edge of the cliff at the man, twisted and motionless, far below.

If we had looked back we might have seen the naturalist shake his head in a manner strangely reminiscent as he turned and gazed again after us.

CHAPTER X

THE CONSPIRATORS