re's the shark?"

"I don't see it."

"There it is," exclaimed Fred. "Between John and the shore."

Sure enough, the great black fin appeared once more sailing serenely
about a few yards distant from John, but between him and land.

"How can he get in?" cried Fred. "The shark is in the way."

"I don't know," said Grant. "Certainly he can't swim right at the
shark."

"He never will get in," moaned Fred. "He'll surely be killed."

"He's all right so far."

"I know. He missed him before but he won't again."

"Maybe John can fight him off. You can't tell."

"There he goes again. He's closing in."

The shark did seem to be moving towards John once more. Around and
around in circles he went and even from the shore Grant and Fred could
see their companion's head turn so as always to keep his eyes fixed on
his enemy.

"We must go to him," cried Fred. "We must do something."

"What can we do? We're helpless."

"Can't we swim out?"

"Suppose we did. We couldn't do anything when we got there."

Suddenly the splashing was resumed. John and the shark both disappeared
from sight as the water was thrown up in all directions around them.

"What's happened, Grant? I'm afraid to look."

"I think he drove him off."

"Are you sure?"

"Yes. There he is. He scared him away again."

"He can't keep that up forever, though," moaned Fred. "He must be
getting pretty nearly exhausted by now."

"Look!" cried Grant suddenly. "Here comes Sam."

Running towards them at top speed and throwing off his clothes as he ran
came Sam. In his teeth was the long knife he had made so laboriously and
spent so many hours to sharpen.

"What's he going to do?" cried Fred in wonderment. "Where are you going,
Sam?" he called as the negro came up to the spot where the two boys
stood.

"Ah'll get 'im," muttered Sam, and without waiting for another thing he
plunged headlong into the water. A moment later he reappeared, the knife
still in his mouth, and with powerful strokes struck out for John and
the hungry giant that threatened him.

"What's he going to do, Grant?" exclaimed Fred.

"I don't know. Watch him."

"Do you think he can kill the shark with that knife?"

"He's evidently going to try."

"He'll be too late."

John was perhaps a hundred and fifty yards from shore now. Slowly he was
nearing land and safety, but could he reach it? The great shark still
circled around and around the unfortunate boy, evidently waiting for
some