At first Oshima did not understand; but he saw the other's gesture, and looked over his shoulder. There, not a hundred yards away, was the dreaded black fin, glistening in the afternoon sun, drifting rapidly toward him like the sail of a child's toy-boat. The swimmer struck out for the shore with all his might. He was in a little bay, and Oto, springing down headlong over the rocks, perceived that his friend was a little nearer the southern point of land than the central beach from which he had started. "Make for the point--the point!" he shrieked, gesticulating wildly. Oshima veered to the right, and the black fin followed. Oto plunged into the sea and swam straight toward the shark. There was no more shouting now; only two dark heads bobbing in the waves, and the little black sail dancing toward them. Oshima now began to beat the water with his hands, making a tremendous splashing. The great fish, startled by the commotion, paused, and the ugly fin seemed irresolute. Oshima was now swimming more slowly. Younger than Oto, and far less robust, he was becoming exhausted. Every moment he expected to feel the clutch of those terrible jaws. He struck out madly, but made little progress. The shark, meanwhile, made up his mind. The new morsel was coming directly toward him, while the first seemed in a fair way of escaping to shallow water if not to the land itself. The monster, with a twist of his tail, turned again and made for Oto, though not very rapidly, for the splashing made the fish wary. At last the critical moment came. Oto had heard an old pearl-fisher tell of many a battle with the man-eating sharks of the Pacific. As the huge creature began to turn, to seize his prey, the black fin disappeared. Quick as a flash Oto doubled himself in the water and dived. A moment later a red stain dyed the surface of the sea. The boy had drawn a sharp dagger from his belt and stabbed upward as his assailant passed over him. There was no more battle. The shark had enough of Oto and fled for the depths of the ocean while his victor, watching sharply for his late foe, made his way ashore as swiftly as possible. He found Oshima stretched upon the sand, uninjured but almost unconscious from fright and exhaustion. It was this incident, the self-forgetful valour of his son's friend, saving the former's life at the peril of his own, that led Oshima's father, a few days afterward, to make the offer that changed the boy's whole life. He proposed to the elder Owari to send Oto at his own expense to any naval school in the world, and educate him for the Japanese navy. Oto chose the United States Naval Academy at Annapolis, as we have seen, and graduated with honour, resigning only to accept a post under his own Emperor.