"That makes it all the more urgent for me to find some aid," he said to himself; "I don't think that bunch on the motor boat will trouble to look for me. I guess they'd be glad to leave me here if this is a deserted island. In that case, I might die here before aid came." But thrusting all such thoughts as that aside, Rob determined to meet the situation like a brave Scout. "I won't give up till I'm at the last ditch," he said to himself with determination, as he put on his clothes. "I'll fight it out to the end." Somehow this resolution of his made the boy feel better. With renewed courage he set out to explore the island. But he made the circuit of it in vain. There was not a trace to be found of human habitation nor any indication, except the stranded, sun-dried boat, that anyone but himself had ever landed there. So despondent did he feel over this discovery that had he possessed the strength to do so, he would have swum back to the other island and thrown himself on the mercy of his recent captors. But this was now out of the question. Unless he could find some way out of his dilemma, it looked as if he would indeed be doomed to leave his bones on those sands. The thought was a dreadful one, and although it was a warm, almost tropical day, the boy shivered and cold sweat ran down his face. If he were indeed to die there, nobody would ever know his fate, in all probability. He had failed in his mission to recover the papers, too. Altogether he felt in a very miserable frame of mind. It was in this mood that, in order to keep his mind off his predicament, more than anything else, he fell to examining the old boat again. There might be some way to patch her up, he thought desperately, hoping against hope. Suddenly he made a discovery that set his heart to beating wildly. On the stern board of the boat was cut the name "_Good Hope_!" CHAPTER XXV. THE DEAD MAN'S HOARD. The "_Good Hope_!" What a crowd of memories the name brought buzzing about the boy! The lone derelict, the figure in the mouldering cabin, the--the plan in his pocket! With fingers that trembled Rob drew out the solution of the cryptogram and read it over. Then he held his head in his hands a moment to keep it from whirling round. Could it be possible that this was the island where the hoard of century-old ivory was buried? Had he stumbled by a complete accident upon the cache that had sent one man to his death? Then he recalled that on his trip of exploration he had noticed a big dead cypress on the other side of the island. But if this was the veritable island where the whalers had buried their ivory, why was the boat lying there mouldering on the beach? Why had they not left again? The more the boy thought of it, the more mysterious and inexplicable the whole thing became. He resolved to go back to the dead cypress and follow the directions of the cryptic message of the captain of the _Good Hope_.