“Then it would never do to let the crowd know all that’s happening, would it?” asked Pollard.

Jack, from thinking over the problems that had come up in connection with the spies, had at last let his attention wander to the crowds.  Down at the beach hundreds were taking an afternoon dip.  Other hundreds were strolling up and down the sands.  Children were building sand castles or houses.  A good many small boats were out with pleasure parties.  Yet many, both grown-ups and children, looked positively bored.  They needed excitement.

“How near this crowd came to having something to talk about,” muttered young Benson to himself, with a smile.  “If that mine had gone off last night, no one at Spruce Beach would have felt dull to-day.”

Finding that the afternoon air was making him dull and inclined to gape, Captain Jack turned back from the beach.  He sauntered along the road, and was about to cross it, when he heard a sharp snap.  It was like a subdued shot.

In the same instant a hissing sound went pseu! in front of his face.  A distinct breeze, small though it was, fanned his eyes.  Then chug!  Something landed in the trunk of the tree he was passing.

“That was a shot!” guessed the submarine boy, like a flash, and in the next breath he muttered:  “Aimed at me, too!”

Jack pitched forward, falling upon his face.  If one shot had been fired, another might be as soon as the unknown marksman realized that he had missed.

Several people, near by, fancied they had heard a shot, and turned, curiously.  Then, as soon as Benson was espied lying on the ground a rush was made in his direction.

At that moment Hal Hastings happened to be looking over toward the beach.  Like a flash he was up and away, his magazine falling from his lap to the ground.

“Now, what on earth has taken Hastings off like that?” demanded Mr. Farnum, looking around in surprise.  “There are other people running, too.  Come along, Dave!”

Hal shot his way through the rapidly gathering crowd.  He reached Jack Benson just as the latter leaped up, laughing.

“Why all this excitement, just because I stubbed my toe against a dew-drop and fell?” demanded Benson, laughing.

“Weren’t you shot?” gasped Hal.

“If I was, I’ll make the rascal prove it,” asked back Captain Jack.  “But, now you mention it, I think the tree was hit.”

Jack turned and looked the tree trunk over at about the height of his own head from the ground.

“See here,” he remarked, laying a finger on a small perforation in the bark, “I think a bullet, or something of the sort, went in here.”

“We’ll soon find out then,” proposed Hal, whipping out his jack-knife, opening a blade and beginning to dig.  The crowd grew in size.  Messrs. Farnum and Pollard had great difficulty in forcing their way through.

After some time spent in patient work Hal dug out a steel-jacketed bullet, short and of small calibre.