While the boys had been watching, Barton had lain down, as though tired, on the summit of a near-by dune. As the red light came close in shore, however, he arose, and once more waved his lantern.

At the signal the course of the red light shifted and headed directly toward him. The boys' hearts beat thickly; the time for action was at hand. The bow of the boat they had seen approaching grated on the beach, and two figures sprang out while Barton advanced to meet them.

"Get as close as you can," whispered Rob, as he wriggled forward; "we want to get every word."

Merritt merely nodded; but his silent advance was as rapid as his leader's. Owing to the nature of the ground, they were able to run forward in an almost upright position when they reached the hollows of the dunes, being compelled to cast themselves down only when they topped a rise. Therefore, they were within ear shot when Barton greeted the two men who had disembarked from the boat.

"Well," said one of the newcomers in a voice which plainly betrayed his foreign origin; "well, did you do as you said you would?"

"Yes," responded Barton; "I've got the drawings here. They are not complete, however, and you will have to give me more time."

"As you were told at Bridgeport, before you left for this island, you can have all the time you want, only make the job complete."

"You can depend upon me to do that," was the response. "So long as I'm well paid, I'll sell out all I know, and that's about everything about the Barr submarine."

Here another voice, that of the second man who had left the boat, struck in:

"What about the models?"

"I've got them hidden up here in the sand," came Barton's voice in reply. "I'd have had them ready but two blooming kids trailed me here."

"Trailed you? What do you mean?" demanded the voice of the man who had first spoken and who, with the solitary exception noted, had carried on most of the conversation.

"Why, this Ensign Hargreaves, this Navy dude, saw fit to bring a band of Boy Scouts down here. They're the nosiest kids ever, and I half think they suspect me of not being all I appear to be."

"That's a good guess," whispered Rob to Merritt.

Merritt could not refrain from a quiet chuckle.

"As a long distance and local guesser, Barton takes the palm," he breathed.

"Hush!" murmured Rob under his breath: "What are they up to now?"

"Going to dig up those models, I guess. Barton must have stolen them from the workshop at odd moments."

Right then something happened that gave Merritt a shock. Rob rose to his feet and started toward the beach. The men that the two Boy Scouts were watching had headed inland, evidently to aid Barton in uncovering the hidden models.

"Have you gone crazy, Rob? Lie down here," cautioned Merritt.

"Not much," was the response; "I'm going to do some reconnoitering while I've got the chance."

"What do you mean?"

"That I'm going down to have a look at that boat, and if I can I'm going to shove her off and thus leave those men prisoners on the island."

"By ginger, Rob, you are a great fellow for ideas. If only you can cast the boat adrift, we'll have those chaps bottled up as securely as if they were in a jail."

"Wait here till I come," responded the boy leader. "I won't be gone more than ten minutes."

"I'd like to come with you, Rob."

"No; this is a job I can do best alone."

Rob noiselessly slipped away. The boat from which the mysterious men had landed was plainly discernible as a black blot on the sandy beach. Rob tried to make himself as inconspicuous as possible, but against the white strip of sand he felt as noticeable as an elephant. However, he gained the boat without interruption.

Its bow had been built up, apparently, to make it more seaworthy, and the boy noticed that a small door had been cut leading into the space beneath the raised bow. He had hardly discovered this when he was startled to hear voices close at hand.

It was Barton and his crooked accomplices coming back. Fortunately for Rob, they were behind a dune, so that it was impossible for them to observe him. But in a moment, the boy realized with a thrill, they would be upon him.

Quick as a flash, and hardly realizing what he was doing, Rob sought the only place of concealment close at hand—the space under the raised bow of the boat. He had hardly squeezed into his cramped quarters before the trio of rascals topped the rise.

Rob, with a sinking of the heart, realized at that moment that it would have been better for him to have taken his chances and run away from the scene. But it was too late now. With something that was not exactly fear, but very like it, Rob recognized the fact that he was a concealed passenger, a stowaway, on board a boat on which his presence might cost him his life.

As these reflections ran through his mind the men drew closer, talking about the "clever" work they had done.

"I guess Barr and his Peacemaker can say good-bye to Uncle Sam now," laughed one of them.

"Yes, and the best of it is that Barton will never be suspected," responded the other. "Our government will be manufacturing submarines of the Barr type, while Barr and the United States Government are still in blissful ignorance of the fact that all efforts are for nothing."

"You can bet I never put through a job unless I do it right," struck in Barton with great self-complacency.

Rob, crouched in his cramped place of concealment, flushed with anger. Right then and there he determined that, come what might, he would see this strange adventure of his through to the bitter end. This resolve was still in his mind when the two men shoved the boat off, bade good-night to the rascally Barton, and, all unconscious of their secreted passenger, got under way.

"If I get out of this alive, I'll be lucky," soliloquized Rob as he heard the oars and felt the boat moving through the water. "I wonder if I've done right? At any rate I'm in it now, and, as a Boy Scout, I'm going to see it through."