CHAPTER XXVIII. THE VOICE IN THE NIGHT. The excited lads beat the bushes in vain. Caleb Cooler had disappeared in a moment, as if the ground had opened and swallowed him. It seemed impossible that he could give them the slip in such a manner, but he had. At last four very disgusted and angry boys stopped in a little opening and looked at each other. "We are a set of chumps!" declared Hodge. "That's so!" grunted Browning. "Ought to have held onto the snake all the time," came savagely from Diamond. "Oh, if we had him here now!" "Yaw!" gurgled Hans. "Uf we had him here now he vouldn't done a thing to us!" "I feel like crawling into a hole," growled the big Yale man. "So do I," nodded Hodge; "but I don't know where to find a hole small enough. What fools we are!" "Yaw!" again gurgled Hans. "Vot fools you vos!" "But I'm hanged if I can understand it," said Bruce. "How did he do it? That is what I want to know." "He was within reach at one moment and gone the next." "Let's search again." They did so, but the time was spent in vain. They were close to the rocks which rose above the ground in the vicinity of the quarry, but it seemed an utter impossibility for anyone to hide amid those rocks. They decided to remain in the vicinity and watch for Mr. Cooler, thinking he was in a place of hiding near at hand, and he would be forced to show himself sooner or later. Having decided on this, they scattered somewhat, but were within call of each other. Then they settled down to watch for the man in gray. It became ominously silent there amid the cedars and pines, save when the fitful wind made a rustling. Once a squirrel was heard chattering in the distance. An hour passed, and then Diamond could stand it no longer. He called them together and said: "Fellows, while we remain idle here, those villains may be completing the work of putting Merriwell out of the way. I think we are wasting our time." "So do I," said Hodge. "Und I vos some more," put in Hans. Then they decided to scour the island. If hidden near at hand, Cooler knew they were watching for him, and it was not likely he would make a move. Two hours were spent in wandering over the island, calling to the missing lad. They awoke the echoes in the dark woods, but the echoes were the only answers to their cries. Disheartened and desperate, they returned to the cove in which the yacht lay. They were troubled by fears that something had happened to her while they were away, but when they obtained a view of her, she was seen riding peacefully at anchor. The small boat was there, and Bart was the first to reach it. Suddenly he uttered an exclamation, and then called the attention of the others to a slip of paper that lay beneath a stone that had been placed on one of the seats. A moment later he secured the paper. "There is writing upon it!" he declared. "Read it!" exclaimed the others, pressing nearer.