At Tom’s astounding announcement Frank sank limply onto a thwart. But the next instant he was up, and seizing the resonance coil, hastily connected it to the set in place of the aerial.

“Now signal or tell me when you get them,” he said, as, holding the coil horizontally, he commenced moving it in a wide circle. For a time Tom was silent, motionless, listening with every sense and nerve taut; then, as the coil pointed to the right, he raised his hand.

“There!” he whispered.

Presently he took off his phones. “It’s no use listening,” he declared “we can’t tell what they’re saying. Oh, thunder, why isn’t Smernoff here?”

“Well, we can call to the folks and tell them and they can let Smernoff listen,” said Frank.

“Silly!” cried Tom petulantly. “If we called them, these Russians would hear and either clear out or shut up. And, besides, I don’t believe they could hear them on the submarine. I’ll bet that’s been the trouble all along. They’ve been too far off.”

“Well, what can we do then?” demanded Frank. “If we call for help to get back, these fellows will hear us too. We’re in a nice fix just from chasing that confounded old manatee. First we get lost and then we hear this talking and can’t even tell about it.”

“We might row along until we lose these fellows and then call the sub,” suggested Tom, “if we get so far away we can’t hear them the chances are they can’t hear us. Come on.”

There seemed nothing else to do and so, choosing a channel that led away from the direction whence the sounds had come, the boys rowed steadily for some time. Then they ceased rowing and picking up the coil Frank held it while Tom listened at the set.

For a space no sounds came to his ears and then he started so violently that Frank was almost upset.

“Gosh all crickety, Frank!” he exclaimed. “Something’s wrong. They sound nearer than ever.”

Puzzled and not knowing what to do, the boys sat motionless and speechless. They seemed to be surrounded by the voices coming from both directions.

“Hello,” ejaculated Frank presently, “We’re moving. Look at those trees!”

Tom glanced up. It was perfectly true, the trees were slowly but steadily slipping past them. They were drifting with the current.

“It must be the tide,” declared Tom. “If ’tis we’ll be out of here soon and if we reach the bay——”

“Hurrah, there’s the bay now!” cried Frank.

A few hundred yards ahead they saw the sheet of open water through the trees and with light hearts grasped the oars and started to row forwards, but before they had taken a stroke Tom uttered a smothered cry, grasped Frank’s arm and pointed a trembling finger at the open water visible through a space between the mangroves.

“Look, Frank! Look!” he whispered

Less than two hundred yards distant, plainly visible and moored close to the edge of the swamp was a big submarine! No second glance was needed to verify Tom’s first suspicions; the shattered conning tower left no doubt as to the craft’s identity.

Frank was too surprised and dumbfounded to speak and stood gazing with unbelieving eyes at the submarine so near to them and so totally unexpected.

“Quick!” whispered Tom. “If we don’t watch out we’ll be drifting in sight on that open water. Grab a root or a branch while I push the boat in.”

Seizing his oars, Tom pushed and pulled, forcing the boat close to the trees until Frank could grasp one of the swaying, descending roots and made the boat’s painter fast to it.

“No wonder we heard ’em,” remarked Tom when the boat was secured. “That creek must turn around a corner and we didn’t notice it. Say, what are we going to do now? We can’t wait here all night and we don’t know where to go and we can’t call our folks without those fellows on this sub hearing us.”

“And if we could call your father or Mr. Rawlins we couldn’t tell them where this submarine is because we don’t know ourselves,” replied Frank.

“It’s awful funny we should find it by getting lost after they’ve been hunting for it night after night,” said Tom, “and now what good does it do? I don’t see but what we’ll have to go back the way we came and trust to luck.”

“Huh!” snorted Frank, “and get lost worse than ever. If this sub came in here there must be deep water leading to sea and if we could sneak out we’d be sure to find the entrance to the bay and then we could call our people or hunt along the shore till we found that beach with the coconut grove.”

“Yes, and a swell chance we have of sneaking out!” Tom reminded him. “Just as soon as we went out of here they’d spot us, sure.”

“Well we’ll have to wait until dark, that’s all,” said Frank resignedly. “Of course they’ll worry, but like as not they’ll call for us and we may hear ’em. Then if these chaps hear, it wont be our fault. I know your father said not to hesitate to use radio if we had to, but he didn’t think we’d be alongside this submarine when we needed to. It’s not going to hurt us to wait here a while and we may see something.”

Tom’s sharp “Hisst!” caused Frank to wheel about. A small boat was now beside the submarine and several men were climbing into it. Presently they pushed off, the men took to the oars and to the boys’ horror and amazement the boat headed directly toward their hiding place.

“Gosh now it’s all up!” whispered Tom in terrified tones, “if they spot us or our boat it’ll be good night for us!”

Breathlessly the boys crouched in their craft, shaking with fright, while nearer and nearer came the boat from the submarine. Then, when the two trembling boys felt that their hour had come, that in another instant they must be seen, the other boat swung to one side and disappeared in a narrow channel among the mangroves not fifty feet from where the boys were concealed. In a few moments the sound of the oars and the voices of the men grew faint in the distance and the boys raised themselves and with relieved, fast-beating hearts exchanged glances.

“Did you see them?” exclaimed Tom. “My, weren’t they a tough looking lot!”

“Regular pirates!” agreed Frank. “Did you see that big fellow with the red beard?”

“You bet, and that thin one with the upturned blonde mustache! Gosh, he looked like the Crown Prince of Germany!”

“That dark man was the worst,” declared Frank. “That Indian or nigger or whatever he was—the one with the earrings. Gee, I’d hate to have them get us.”

“I never knew Russians were such ugly looking people,” said Tom, “and I thought they were all light. That fellow with the earrings was almost as black as Sam.”

“They’re not all Russians,” Frank reminded him. “Don’t you remember Mr. Henderson and your father saying they were ‘reds’ from every point of the world and that the big chief of the lot isn’t even a German although he worked for Germany. And there was that man that died in New York, he was Irish.”

“Yes, that’s so,” agreed Tom, “but say, let’s get out of here now. They’re gone and maybe we can sneak away. I don’t believe any one’s aboard the sub.”

“Well, I do,” replied Frank, “I vote we turn back and see if we can’t find another channel that leads out below here. We can tell the right way to go by the tide flowing.”

“Golly, that’s so,” assented Tom. “All right, but we’ve got to be careful.”

Unfastening the boat, the two boys pulled slowly up the creek against the current, searching the mangroves on either side for an opening through which the tide was flowing. At last they sighted one and with elated minds turned into it. As they pulled along, Tom noticed that the mangroves were giving place to other trees, that the soft mud banks had changed to sand and that the shores were getting higher.

“We must be getting out of the swamp,” declared Tom. “See! the banks are high and there are trees. We’ll soon be out.”

The stream they were following was now running with quite a swift current and the boys noticed several side branches or smaller creeks flowing into it. They had just passed one of these and were about to turn a bend when with one accord they stopped rowing, their eyes grew wide with fright and they sat listening breathlessly. From ahead had come the sounds of human voices! Just around the bend were men!

To go on meant certain discovery. What should they do? For a brief instant they had thought it might be some of their own party, but the next second they knew better, for the words that came to them were in a harsh guttural tongue—the same tongue they had so often heard through their receivers.

Then, a sudden desire, an overwhelming curiosity to see the speakers, to learn where they were and what they were doing swept over Tom. With signs he motioned to Frank and an instant later they had run their boat into the side creek, had beached it noiselessly upon a narrow strip of soft earth and like snakes were wiggling silently up the bank among the trees. For some strange psychological reason they were no longer afraid; no longer did thoughts of the risk they ran enter their heads. Their entire thoughts were centered on seeing these men, on learning what they could, for they realized instinctively that they had stumbled upon the secret of the gang’s hiding place, that they had found what their friends had been searching for night after night and that, did they ever regain their own submarine, their knowledge would be invaluable.

But they were cautious. They had no intention of being either seen or heard and before they reached the summit of the bank they carefully raised their heads and peered between the bases of the trees beyond. They had no means of knowing what lay beyond that bank. It might be open land, it might be brush or woods or it might be water. They knew, however, that the men must be close at hand and yet, when they peered through, they could scarcely repress surprised exclamations at what they saw.

Within a dozen yards, a boat was lying beside the bank of the stream and just beyond, beneath a wide-spreading tree, two men stood talking.

One was the big, red-bearded fellow the boys had seen in the boat as it left the submarine. The other, who half leaned upon a repeating rifle and who wore an immense automatic pistol at his belt, was tall, well-built and most striking in appearance. He was dressed in light, neat clothes and leather puttees; a broad-brimmed Panama hat was on his head, his face was tanned but clean shaven, except for a small, sharply upturned, iron-gray mustache, and in one eye he wore a monocle.

So totally unlike his companions was he that the boys almost gasped in astonishment. There was nothing about him, nothing in his appearance, that spoke of lawlessness, of a thug or a criminal. Indeed, he was a most distinguished-looking gentleman, such a figure as one might expect to see at a meeting of scientists, at some state function, at a directors’ meeting in some bank or business house.

But when he spoke the disillusionment was complete. His voice had the strangest sound the boys had ever heard. It was cold, grating, inexpressibly cruel and sent shivers down the boys’ backs as they listened. What he was saying they could not grasp, but that he was angry, that he was reprimanding the giant before him, the boys could tell by his tones, the hard reptilian glitter of his light gray eyes and by the expression of the red-bearded fellow.

The latter, with hat in hand, fairly cowered before the other. His head was bent, his eyes downcast, his face and neck were flushed scarlet and his replies came in a low, humble, apologetic tone.

Those in the waiting boat were silent, only the two uttered a single word. For a space the boys watched, fascinated, and then it occurred to Tom that they must get away, that somehow they had taken the wrong channel and that if they were to escape unseen they must leave at once, retrace their way to where they had seen the submarine and from there try to reach the entrance to the bay.

Touching Frank’s arm, Tom signaled for him to withdraw and as silently as they had come the two boys slipped down the bank, shoved their boat noiselessly into the water and crept into it.

With fast beating hearts they paddled towards the larger stream and had almost reached it, when, without warning, a flock of white ibis flapped up before them and with harsh croaks of alarm perched upon the topmost branches of the trees.

The boys’ blood seemed to freeze in their veins and their hearts to cease beating. Would the men suspect something or somebody was near? Would they sweep down on the boys?

Instantly, at the hoarse cries of the birds, the voices beyond the point had ceased and the boys knew the men were listening, straining their ears for a suspicious sound. To go on would be to court disaster. The least rattle of oars or squeal of rowlocks would be heard and even if no sound issued from the boat the slightest movement would again arouse the ibis overhead. There was nothing to do but wait, wait with panting, throbbing lungs and heart-racking fears for what might happen next.

But the boys did not have long to wait. From beyond the intervening bank came the rattle of an oar, a sharp, gruff order, the splash of water. The men were coming! To remain where they were meant capture! There was but one thing to be done and that was to turn and pull as fast as they were able into the small creek in the one faint hope that the others might pass it by and look for the cause of the birds’ fright upon the main stream. Quickly the boat was swung round and with deadly terror lending strength to their arms, the boys pulled frantically into the trees that formed an archway over the tiny waterway. But their ruse was in vain. The noise of the splashing oars had been heard. The disturbed water of the stream told the story of their flight to their enemies. Scarcely a score of yards had been covered when the boys heard the other boat following, heard the rough Slavic voices, and the frightened cries of the ibis. Madly they pulled and then, so close that the boys could not avoid it had they wished, the creek came to an abrupt end in a mass of foliage.

Before the boys knew it was there they had bumped into it. Frank’s hat was swept off by a branch, sharp twigs and thorns tore their flesh, the boat rocked and grated, and realizing they were trapped the boys screamed in terror. Then, ere they grasped what had happened, their boat had shot through the screen of branches, they were in open water and looking back they saw the fallen trees which had spanned the creek. Before them the stream turned sharply to one side. Only a dozen strokes of the oars would bring them to the bend. They had almost reached it when shouts and curses came from beyond the fallen trees, they heard a crashing of the branches, the sharp reports of revolvers rang out and bullets whistled past the boys’ heads.

The next moment the boat shot around the point and, driven to desperation, thinking only of outdistancing their pursuers, the boys rowed like mad, giving no heed to direction, no attention to their surroundings. Then they suddenly realized that the sounds of their pursuers had ceased, that there were no shouts, no splashing of oars, no rattle of wood on wood. What had happened? Why had the others abandoned the chase?

And then it dawned upon Frank.

“Gee Christopher!” he exclaimed under his breath, “that fallen tree saved us, Tom! Their big boat couldn’t get through. We’re safe!”

“Gosh, I guess you’re right!” whispered Tom while the two still continued to row. “But I’m not sure we’re safe. There may be another way in here and perhaps they’ve gone around to cut us off. Say, we’ve got to row like the dickens and try to get so far they won’t find us!”

“Yes, but we’re lost!” declared Frank. “We haven’t any idea where we are!”

“I know it,” admitted Tom, “but we can’t help that now. After we’ve gone farther we’ll stop and call our folks. Those chaps back there can’t hear us and if their sub does, it won’t make any difference now. They know we’re here and we’ve got to get out.”

For fully half an hour they toiled on. Their breath came in gasps, their arms ached, their hands were blistered and raw, but they dared not stop. Then, when they felt they could go no farther, their boat shot out from the mangroves and they found themselves floating on a broad lagoon.

“Hurrah!” cried Frank, “we’re back where we saw the manatee!”

“Golly, so we are!” agreed Tom. “Well, I’m going to use the radio now and see if we can get our people.”

But all attempts to get their submarine proved fruitless. Over and over again they called. Hopefully and patiently Tom listened while Frank moved the resonance coil about, but not a sound came through the receivers.

“It’s no use,” declared Tom at last. “We can’t get them. What on earth will we do?”

“All we can do is to go on,” replied Frank in dejected tones. “It’s almost dark, we may find our way by luck.”

“I can’t row another stroke,” declared Tom. “I’m all in. We might just as well lie here and rest, at least until the moon comes up. We can’t go on in the dark through these creeks.”

“Yes, I suppose so,” agreed Frank who, now the excitement was over, felt utterly exhausted. “We’re as safe here as anywhere.”

Drawing in their oars the two lonely, tired and hungry boys threw themselves in the bottom of the boat and too weary even to talk lay gazing up at the stars. The boat rocked gently to the tiny ripples on the lagoon; from the swamps came the droning chant of frogs and insects; fireflies flitted by like tiny meteors; the water lapped soothingly against the boat’s planks and lulled by the sounds and the soft night air the boys slept.

Tom was the first to awake. For an instant he lay still, dazed, not remembering where he was and dimly aware of a strange, monotonous, resonant sound that somehow seemed to vibrate and throb through his brain, the boat and the night air.

He nudged Frank. “Wake up!” he half whispered, “wake up! The moon’s out and we’ve got to be going on.”

Then, as Frank sleepily opened his eyes and yawned, Tom spoke again.

“Hear that noise?” he asked. “What is it?”

Frank, now wide awake, sat up. He too heard the sound, a noise so unlike anything else he had ever heard that he felt cold shivers chasing up and down his spine.

“I—I don’t know!” he stammered. “It’s uncanny—perhaps it’s a frog or a night bird or something. Say, where are we?”

Then, for the first time, Tom noticed their surroundings. No longer were they on the lagoon. On either side, rose tall trees looming black and gigantic against the moonlit sky and by the glint of the light upon the ripples the boys could see that the narrow waterway ran swiftly.

“Crickey, we’ve drifted while we were asleep!” cried Frank. “Now we are lost.”

“Well, we’re drifting with the tide anyway,” said Tom, trying bravely to be cheerful. “And it’s bound to take us out somewhere to open water.”

“Yes, only it may be coming in and not going out,” said Frank. “What time is it? My watch stopped when I fell overboard.”

Tom pulled out his watch and examined it’s luminous dial. “Gosh, it’s after eleven!” he exclaimed. “Say, we must have slept four or five hours.”

“There’s that noise again!” cried Frank. “What on earth is it? It seems to come from all around and say—— Gee, look there, Tom! What’s that?”

Startled, Tom glanced about. Far ahead between the trees he could see a ruddy glow.

“Golly, it’s a fire!” he exclaimed in frightened tones. “Let’s get out. It may be those Russians again. Perhaps it’s their camp.”

“And the noise comes from there!” stammered Frank. “It’s dreadful!”

Hurriedly grasping their oars the boys pulled, trying their utmost to swing the boat’s bow around, but it was of no use. The current was running like a millrace and despite their utmost endeavors they were being swept irresistibly towards the fire and that weird, uncanny, hair-raising sound.

Nearer and nearer they swept. Now they could see the ruddy light upon the water ahead. They could even see the flames dancing among the trees and the resonant, throbbing boom rose and fell in terrifying cadence through the night. Then, between the throbbing beats, the boys heard voices; but not the harsh guttural voices of the “reds.” It was even worse, for the sounds borne to the boys—frightened, terror-stricken and helpless in their drifting boat—savored of savages. They were high-pitched, yet musical, rising and falling; one moment dying to a low murmur, the next rising to a blood-curdling wail.

Absolutely paralyzed, the boys sat and stared at the light and the fire they were approaching. What was it? Through their minds flashed stories of cannibals, visions of savage Indians, and yet Rawlins had assured them there were no Indians upon the island. But surely these could be nothing else. Those sounds—dimly, to Tom’s mind came memories of a similar sound he had once heard—yes—that was it—an Indian tom-tom at a Wild West show. They must be savages! Yes, now he could see them, wild, naked, dancing, leaping figures; whirling, gyrating about the fire now less than two hundred yards ahead and within fifty feet of the Lank. Frank had seen them also. He too knew they must be savages. Would they be seen? Would the dancing, prancing fiends detect them as they swept through that circle of light upon the water or were they too busy with their dancing to notice them? Now the drum roared in deafening, booming notes, filling the surrounding forest with its echoes and the savage chant of the prancing figures sent chills over the cowering boys. Just ahead was the expanse of water illuminated by the red glare. In a moment they would be in it. Close to the bank the boys saw canoes drawn ashore, big dug-outs, crude primitive craft. Yes, there were Indians in Santo Domingo, Rawlins must have been mistaken. Now they were in the firelight. They held their breaths and then a moaning hopeless groan issued from the boys’ lips. Their boat slowed down; before they realized what had happened they were caught in an eddy and the next instant their craft bumped with a resounding thud against one of the canoes.

The boys’ senses reeled. They were wedged fast between the dugouts in the brilliant light from the fire and before a cry could escape them, before they could move, two half-naked, awful creatures, hideously painted and with threatening, waving clubs came dashing down the bank.

The boys knew their last minute had come. The savages had seen them. Resistance would be hopeless. They were too frightened, too frozen with mortal terror to move or even scream.

The next second the naked fiends were upon them. Powerful hands seized legs and feet and unresisting, limp, almost unconscious with dread thoughts of their fate, they were borne triumphantly towards the fire and the ring of terrifying figures.