For a moment the jaw of the ungainly man dropped and he stared blankly at the boy. "What do you know about it?" he said at last. "Not very much," laughed Fred. "If you want to go with us I'll see if Mr. Button is willing." The consent was readily obtained and in a brief time the party which now consisted of six started toward the shore where their motor-boats were waiting for their coming. It was not long before all were on board, Rufus insisting upon taking his place with Fred and John. It was on the same boat also that Mr. Button sailed. For a time, until the shores of Cockburn Island could no longer be seen, silence rested upon the party. No one appeared about the house as they looked back at the island from which they had come. Not even the dogs now could be seen. It was then that Mr. Button turning to the boys said, "I fancy you boys are anxious to know what all this means." "Yes, we are," said Fred quickly. "We know a little, but not very much about it." "This man," explained Mr. Button, "is one of the most expert smugglers of diamonds in America. Sometimes he comes to New York, sometimes to Boston and then again he lands at New Orleans or Baltimore." "Why hasn't he ever been caught?" inquired John. "He was caught once and brought to trial, but on some technicality he went free. I had word that he was trying a new tack. Several times he has landed at Montreal and then coming up the river has made his way across the border hereabouts and taken his goods either to Chicago or Buffalo. But we have run the rascal down at last." "But you haven't got him," protested Fred. "That's true. I couldn't take him on Canadian soil without extradition papers. I have his diamonds, however, and he prefers to give them up rather than take any chances of being arrested and handed over to our government." "It's a strange way to smuggle," said John thoughtfully. "All smugglers are strange. I have been in the employ of the government a good many years and I never have found one that wasn't 'strange.'" "What do you suppose those diamonds are worth?" inquired Fred. "According to the word we have received," replied Mr. Button, "there are diamonds in that box valued at from $10,000 to $15,000." "Whew!" said John. "I guess I will hand it over to you right away. You had better take it," he said as he drew the box from its hiding place and handed it to the Government Agent. "I want to thank you boys for the part you have taken," continued Mr. Button, "and I shall not forget about other rewards. I think the first real evidence I had came when the clerk at the hotel by mistake gave you my letter. Why did you write those letters!" he added turning abruptly upon Rufus, as he spoke. "What letters?" demanded Rufus. "About the smuggler."