"By Chorch!" exclaimed the Dutch boy, turning pale; "I don'd vant to monkey aroundt dot island all alone by yourself." "Do you have any idea what the mystery of the island can be, Merriwell?" asked Hodge, eagerly. "Of course I do not know any better than yourself, but I have a suspicion." "What do you think?" "Yaw!" cried Hans; "vat do I think?" "I believe some kind of unlawful business is carried on there, and for that reason the criminals are using every means to frighten away anybody who might prove troublesome or inquisitive." "Then will it pay us to be troublesome and inquisitive?" said Diamond. "That is the very matter we are here to discuss. The girls and Miss Gale are comfortably located here at Green's Landing, and they will be able to amuse themselves for a day or two. If we wish, we can run down to Devil Island every morning and return here every night. I am willing to confess that my curiosity is aroused, and I would give something to solve the mystery of the place; but I do not wish to drag any of my friends into danger where they do not wish to go." "I hardly think there is one in this party who will not stand by you wherever you go, Merriwell," said Bart, quickly. "You can count on me." "I knew it." "And me," grunted Browning. "I thought so." "Und I vos anodder!" exclaimed Hans. "That is good." "Don't think for a moment that I will go back on you," said Diamond. "I started on this cruise with the intention of staying with you, and I shall." "Good. That part of it is settled. I have said that the mystery of that island belongs to me, and I will solve it. I mean to keep my word." "Vale," said Hans, "I never knowed yourseluf ven you didn'd keep your vord, Vrankie. But maype you don'd vant to took some more chances uf peing runned ofer a railroat on?" "Hardly. We have a fair breeze. Shall we run down to the island this forenoon?" "Come on," said Diamond, suddenly. "If we have a mystery to solve, the sooner we get after it the better." There was a thump against the side of the yacht, and a voice called: "Ahoy on board there! I want to see the captain of this craft." CHAPTER XXII. THE MAN IN GRAY. When Frank reached the deck he saw a jolly-looking little man in gray clothes coming over the rail. Beside the yacht lay a dory, in which sat a fisherman who had rowed the old man off to the _White Wings_. "Dang a dory," exclaimed the little man in gray, with a chuckle. "She may be all right to row round in on a troubled sea, but she'll tip quicker'n scat if you step up on the side of her. This one near spilt me into the drink after I was alongside here. What I want is a flat-bottomed scow or raft. I hope this yacht is good and steady, for I'm going to take a cruise in her." "You are?" gasped Frank, smiling. "Well, that is cool." "Of course," nodded the little man, brightly. "Everything around me is cool, even to my name, and that is Cooler--Caleb Cooler." "I like your nerve!"