Hank was landed at the spot agreed upon, a short time later, and the other three then resumed their journey for the hydroplane’s home port.  As they turned seaward Jack pointed mockingly to Topsail Island, which lay a short distance on their port bow.

“I’ll bet there’s plenty going on there right now,” he grinned.

“Right you are,” assented Bill.

“Hullo,” he added hastily the next moment; “what’s that?”

He pointed toward the island, and the occupants of the homing hydroplane saw, slowly rising from it in the still air, four straight columns of blue smoke.

“Looks like a signal of some kind,” suggested Jack after a scrutiny.

“It’s coming from about the place where we grabbed the kid,” added Bill, a note of apprehension in his voice.

“I wonder what it signifies?” demanded Jack, whose face began to bear a somewhat troubled look.

“I can tell you,” said Sam shortly, turning round from the wheel.

“You can?”

“Yes.”

“Well, hurry up, then—­what does it mean?” Jack spoke sharply at Sam’s deliberation.

“It means,” said Sam slowly, as if he wanted every word to sink in, “that the Boy Scouts have picked up your trail.”

CHAPTER XX

THE HUNT FOR TENDERFOOT JOE

Rob, Merritt, Tubby Hopkins and Captain Hudgins rested, perspiring under the noon-day heat, on a group of flat rocks at the highest point of the island.  Their search had been fruitless, and their downcast faces showed it.

“How ever are we going to break the news to his parents?”

Merritt it was who voiced the question that had been troubling all of them.

Before any one had time to frame a reply the captain, whose keen eyes had been gazing about him, gave a sudden shout: 

“There’s that smoke yonder yer boys were lookin’ fer,” he exclaimed, pointing.

“Four columns of it,” shouted Rob, “hurray, boys, that means news!  It’s ‘Come to counsel.’  Come on, don’t let’s lose any time in getting back.”

Rapidly the boys stumbled and ran forward over the rocks and pushed on among the dense growth that covered the hillside they had climbed.  They hardly noticed the obstacles, however, so keenly were they bent on getting back to camp and learning the news which they knew must be awaiting them.  They covered the distance in half the time it had taken them to ascend the hillside and were met in the camp by the body of searchers—­Andy Bowles, Sim Jeffords and Ernest Thompson—­who had swung off to the left or mainland side of the island.

“Well, boys, what news?” breathlessly exclaimed Rob, “we saw the counsel smoke and hurried down at top speed.”

“Well, there’s not very much, I’m afraid, Rob,” began Andy, “but we found something that may give us a clue.  About half a mile down the beach there’s the distinct mark of a boat keel where it was drawn up on the hard sand and the marks of three separate pairs of feet.”