He felt about, and soon made out that the chimney was made of rough stone, with rather wide interstices between each boulder. It was an easy matter to clamber up it, and soon Ned was on his way toward the stars framed by the top of the structure. But when he had reached a height of some ten feet above the cellar floor, a strange thing happened. One of his feet struck a part of the chimney, which gave out a hollow sound. Moreover, the sound was that of wood.

“Guess that there must be a fireplace opening there,” thought the Dreadnought Boy; “evidently, they had it boarded up for the summer, or maybe the chimney was never finished. Guess that must be it. Now, the question is, what lies beyond that board?”

As if in answer to his unspoken thought, he heard, at that moment, a distinct groan coming from the other side of the board.

“That must be Mr. Lockyer,” was the boy’s instant thought; “wonder how tight this board is?”

A hearty kick soon solved the question. The board flew outward into the room with a clatter, and the next instant Ned beheld the face of Channing Lockyer once more. The inventor was seated at a table in a room which, apparently, contained no other furniture beside that and the chair to which, in a close view, it became apparent he was tightly bound. In one corner of the place a lamp, on a high shelf, shed a sickly light.

“Mr. Lockyer!” cried the boy.

The inventor met his gaze with a half-dazed look that somehow sent a creepy feeling through the boy. Crossing the room in a few steps he shook the other’s shoulder.

“Mr. Lockyer? I’ve come to save you. What is it? What’s the matter?”

A hollow groan was the response, and the inventor, who had, seemingly, been partially roused when the chimney-board fell in, let his head sink forward on the table once more.

“By George!” exclaimed Ned, with a sudden remembrance; “I recollect now. Those fellows did say something about having drugged him. The stuff seems to be still working. Whatever will I do? They’ll be back before long, and we ought to be out of here.”

Reasoning that it would be probably his best course of action to cut the inventor loose, Ned drew his knife, of which his captors had not bothered to deprive him, and slashed the ropes that bound Channing Lockyer to the chair. As his bonds relaxed, the inventor slid heavily forward and sank in a heap on the floor.

“Well, if this isn’t tough luck,” groaned Ned; “what am I to do? I can’t carry him far, that’s certain. Guess I’ll open the door and see if the fresh air will revive him.”

He swiftly was at the portal. But it would not yield to his tugs.

“Locked on the outside!” exclaimed Ned; “I’ll try the window.”

That, too, was locked in some way he could not discover. But Ned was not one to be beaten by trifles like that. Picking up the chair, he swung it against the casement, carrying away sash and all. The blast of keen sea air that swept in seemed, to Ned’s delight, to revive Mr. Lockyer. He stirred like a man awakening from a long sleep.

“Come, sir, come!” cried Ned, lifting him; “can’t you stand?”

“I—what has happened?” asked the inventor thickly. He stared about him with a blank look.

“You’ve been drugged by rascals, but I’m going to get you out of here,” rejoined Ned; “come, sir; rouse up. Ah, that’s better,” as the inventor, with the lad’s aid, got to his feet. He stood staggeringly, and then Ned, as gently as he could, half-dragged, half-carried him to the window.

“Have to lift him through,” thought Ned, as Mr. Lockyer gazed blankly about him. Evidently he had little knowledge of what was happening.

Putting his strong, young arms about the inventor’s slight form, Ned lifted him through the window. Then he followed.

“A fighting chance,” he breathed, as, gathering up Lockyer in his arms, he began a staggering run across the heavy sands. Coarse grass grew upon the island, which bothered him a good deal, but in the emergency before him, Ned seemed endowed with superhuman strength.

As one direction seemed as good as another, he did not pay much heed to where he was going. Before long he reached the margin of the island. At least, he could hear the ripple of tiny waves on the beach.

“Good land,” breathed the lad to himself, setting down Mr. Lockyer’s limp form, “it will be child’s play to find us now. If only there were some way to escape from the island, but I guess there isn’t, and we’re out of the frying pan into the fire.”

It was a bitter pill to swallow. To have come so far and surmounted such obstacles only for this! For Ned, against all manner of reason, perhaps, had treasured, deep down in his heart, a hope that, after all, what he thought an island might turn out to be a part of the mainland. He realized that there was no use dwelling in this fool’s paradise any longer.

As he stood there under the stars, without a hope left, a sudden sound was borne to his ears. It was as ominous an interruption to the hush of the night as could be imagined.

The swift, sharp chug-chug of a motorboat’s exhaust.

To Ned, it meant only one thing. Ferriss and his companions were returning. In a few minutes they would have discovered the escape and then would scatter and search the island. In that case, their recapture was inevitable.

“Well, Ned Strong,” said the Dreadnought Boy half-aloud, “this looks like the beginning of a particularly lively end.”

But to Ned’s stark astonishment, the next instant a familiar sound came over the water from the direction in which the approaching chug-chug was manifest.

“Jer-us-o-hos-o-phat, shipmates, my advice is ter cruise back to the submarine. Wherever them varmints has taken Ned Strong and Mr. Lockyer, we won’t be able to find ’em. Not to-night, anyhow.”

“Which is just where you’re wrong, Tom Marlin!” hailed Ned, his voice fairly aquiver with gladness.

“A-h-o-y!” came an amazed hail from the water. “Ned Strong, my hearty, are you there, or is it your ghost?”

“It’s me, dear old Tom; but hurry and get alongside there. Is Herc with you, and young Sim?”

“Here safe and sound, Ned,” shouted the well-known voice of the red-headed lad; “thank goodness, we’ve found you.”

“And Mr. Lockyer, too,” shouted back Ned, in response to the glad shouts that came in a perfect torrent from the other boat.

“What! How on earth——?”

“Never mind that now. Never mind anything now but getting that boat in here as close as you can. They’ll be coming back before long.”

Not stopping to ask who “they” might be, the boat was run close in to the shore till not more than a foot of water was between her keel and the bottom. Then Ned, picking up the still half-dazed inventor, waded out to her and, presently, they were safe aboard.

“Say!” exclaimed the reporter, as Ned swiftly told his story, “let’s stay here and give those rascals a fight.”

“I’d like to,” said Herc wistfully; “maybe we could arrest them and land them where they belong, which is in jail.”

But Ned vetoed the proposition. For one thing, it was important to get Mr. Lockyer back to where he could have medical attention, for whatever kind of stuff the rascals had given him, it seemed to have completely overcome him. He sat in the bottom of the launch with a vacant look on his face. The little craft was, accordingly, put about and headed for Grayport. As they chugged along Herc told how they came to happen along at such an opportune moment for Ned.

After they had heard the auto speed off, they had given chase for a while, but had finally desisted when they saw it was useless. Then they began to look about for Ned, and discovered that he was gone. For a time they were at a despairing standstill, but, after a lot of discussion, it was agreed to head up the Inlet toward the islands, as Reporter Hargraves recollected having heard the ruffians, who had abducted Lockyer, mention the islands in their talk in the summer house. They had been cruising around for some time among the deserted summer colony of bungalows and islands, and were about ready to give up the search when they heard Ned’s hail.

On the way back to Grayport they encountered something which was to have played an important part in Ferriss’s plans. This was the drifting boat in which Gradbarr had rowed Lockyer ashore. Drifting about, bottom up as she was, they almost ran her down in the darkness. On turning her over, they found that Anderson had carried out his instructions to the letter, for under one of the thwarts was Mr. Lockyer’s hat.

“Gracious!” exclaimed Herc, with a shudder, “suppose we had not found you and had encountered this boat on our way back? We would have given up Mr. Lockyer for lost for certain, and your fate would have been a mystery to us.”

No time was lost in reporting on board the Lockyer, where anxiety and apprehension were naturally at fever heat. Lieutenant Parry and Midshipman Stark had returned some hours before, but they were pacing the deck, on the lookout for news of some sort, when the launch, with the returned adventurers, arrived.

Warm, indeed, were the congratulations showered upon the lads and the reporter, who had aided them so materially. Mr. Lockyer was placed in a bunk, and Lieutenant Parry, who had some knowledge of medicine, administered some remedies to him. Such good effect did they have that when a doctor came from the shore in the morning there was not much for him to do, except to look profound and recommend rest.

The police were communicated with, and a force of men sent to the island on which Mr. Lockyer had been imprisoned. Evidences of a hasty flight were found there. Evidently, Ferriss and his companions had returned, and finding that in some mysterious way their prisoners had escaped, had not deemed it wise to linger.

The auto had been hired, it was discovered, from a reputable garage in the town. As for the bungalow, that had been rented by Ferriss some days before. He had represented himself as an invalid anxious to try the fresh-air cure, and the real estate agent who rented the place to him had had no suspicion of the real purposes for which he wanted it. Although a “general alarm” was sent out for all who had taken part in the dastardly night’s work, no trace was discovered of them in Grayport or the vicinity.

“I guess they’ve fired their last gun,” commented Ned, when this information was brought off to the submarine that evening. But in this the Dreadnought Boy was mistaken. Such men as Ferriss do not accept defeat kindly. It only enrages their degraded natures and makes them hungry for vengeance on those who they deem have thwarted their ends.