not shown himself the prig Cavanaugh made out. He had not said a word against the others going in. He had even been conscious of an awkward sense of embarrassment at not joining them himself.

Suddenly, out of the turmoil of hurt and longing and regret, came the desire to win back at any cost what he had lost. If he went in with the rest wouldn’t Cavvy realize that he had been too hasty, and perhaps make amends? It wasn’t too late. McBride and Hinckley, who had stripped more leisurely, were even now moving slowly toward the spring-board. If he hurried—

Instinctively the boy bent down and untied his shoe laces with a jerk. Then he straightened slowly, face flushed and jaw squaring. He couldn’t do it. Something within him made the thing impossible—the action of a coward and a weakling. What sort of a Scout would he be to deliberately fling overboard his principles and do a thing he felt to be wrong for the sake of winning another’s approval? And what was that approval worth which could be won in such a fashion?

Downcast, motionless, the boy stood fighting out his brief mental battle. He was unaware of the curious glances and low-voiced comment of Ferris and Ritter, sitting together a little to one side. For a space he did not even notice the three fellows in the water save to be conscious of their splashings and sputterings and occasional peals of laughter—laughter which grated somehow, and made him feel like one apart. Then Cavanaugh’s voice, still sharp and a little pettish, brought his head up and his troubled gaze sought out the fellow who had been his friend.

“I’m sick of this fooling,” he heard Cavvy say. “I’m going for one last decent swim.”

“Better not go out too far,” advised Hinckley joshingly. “Remember the shark.”

Cavanaugh disdained reply. Already he was heading out from the shore, cleaving the water with a swift, overhand stroke. Steve watched him wistfully, and presently a faint touch of uneasiness began to grip him. Spectacular as he was at diving and other water “stunts,” Cavvy had never showed up very well when it came to long distances. He explained this once to Haddon by saying that several times he had been attacked by cramps and had learned to be careful. Suppose a cramp should seize him now with scarcely anyone around to help, thought Steve, and instantly his uneasiness changed to acute worry. In troubled silence he watched the fellow draw further away from shore until at length he could not restrain himself.

“Why doesn’t he turn back?” he exclaimed aloud. “He’s crazy to go out so far.”

“He’s got more nerve than I’d have,” commented Ritter. “Suppose that shark should show up now? Where would he be then, I’d like to know.”

“I wasn’t thinking of that,” returned Haddon, who had been inclined to agree with Cavvy’s side of the shark argument. “But he’s liable to cramp, and if he should be—”

He broke off with a sharp intake of his breath. Out in the Sound Cavanaugh had turned suddenly about and was making for shore with a wild splashing haste which told instantly of something wrong. For a second Steve stood rooted to the spot. Then he ran toward the spring-board, pulling off his shirt and jerking at the buckle of his belt. As he paused a moment to kick off his shoes and slide out of the scanty shorts, a shrill, inarticulate cry of horror from Ritter urged him on. It was the cramp, then, just as he had feared. But Cavvy was still keeping up. He was even making progress shoreward in spite of that frantic splashing which wasted so much strength. If he only kept his head—

“The shark!” screamed Ferris suddenly behind him. “The shark!”

CHAPTER III
THE SHARK

Steve’s feet were on the plank before the meaning of the words stung into his consciousness. As he ran, his startled gaze swept over the glinting water and for an instant his blood froze. Beyond the struggling Cavanaugh, but much nearer to him than the latter was to shore, something thrust up above the water—something thin, triangular, erect, dull gray in color, that cut through the little waves with swift, smooth, gliding ease.

To Haddon it seemed as if the plank slid backward under his feet. His dive was purely instinctive but it was a fine one, wide and shallow, that carried him well out. As he shot to the surface he almost collided with Ted Hinckley, but he was quite unconscious of the other’s nearness. Out of that numbed daze of horror and dismay but one thought, one motive, rose to dominate him. He must reach Cavanaugh before the shark.

What he could do then he did not know. But as he tore through the water with that powerful overhand stroke which had won him many a race, his sturdy self-control began slowly to return. Little by little scraps of things came back to him, things he had read and heard, some of them part of that very discussion on the beach so short a time ago. Noise! That was the thing. Sharks were afraid of noises. If he could only reach Cavvy in time there might be a chance—

His hands struck the water with an even, rythmical slap-slap. Though he had not slackened his stroke, it seemed as if he were merely crawling. The temptation to increase his speed was almost irresistible, but he conquered it by deliberate effort. Already he was breathing hard, and he knew that unless he kept back some of his strength he would be helpless at the crucial moment.

At almost every third stroke his dripping face flashed up out of the water and his desperate gaze searched the wide expanse for a sight of that ominous fin. Twice he found it; once circling off to the left of where Cavanaugh was swimming, whereat he was thrilled with hope that the creature had abandoned the pursuit. But the next time it was cutting through the ripples straight toward Cavvy, and the sight made Haddon throw caution to the winds.

With every remaining ounce of strength he lunged forward. His muscles ached, his lungs were bursting. But still he managed to send his weary body sizzling through the water at a racing speed. Then Cavanaugh’s face flashed up before him, strained, white, panic-stricken, and he slowed down.

“Keep on, old man,” he gasped. “Go straight ahead. I’ll stay—”

He did not finish. Already Cavvy had passed him and was laboring shoreward. Steve gulped in the precious air, took a few long strokes forward and stopped with a sudden gasp. The fin had disappeared!

The moments that followed were like nothing that he had ever known. Cold horror gripped him by the throat and choked him—that horror of the unknown which is so potent and so paralyzing. The shark had dived and was swimming under water. At any moment he might feel—

For an instant he came close to screaming wildly, to beating the water with that mad frenzy which comes to drowning men. But just in time his teeth dug cruelly into his under lip and he jerked himself back into a semblance of sanity. And then he began to shout and beat the water, but with a set purpose. Noise was what the creature dreaded. He could not hope to outswim the monster, but in this fashion he might hold it off till Cavanaugh was safe, and perhaps himself.

Ceasing his clamor he swam shoreward a dozen strokes and then paused again to splash and shout. Again and again he did this, and each time it was harder to make that deliberate pause. He was possessed by a panicky desire to speed ahead, trusting to his swiftness. Once he did let himself go and swam perhaps a score of strokes without stopping. When he finally forced himself to halt and