"I wonder what's the matter," he went on. "Can Martin have forgotten to sound the tocsin? It's the first time he ever slipped up." A little later there came the sound of persons moving in the hall, and then voices could be heard calling one to the other. He got out of bed, finding that his ankle was much better and looked from the window. There was nothing out of the ordinary to be seen. He turned toward his door, just as a loud knock came on the portal. "Who's there?" he asked. "Martin, the monitor," was the reply. "Dr. Mead wants to see you at once in the office." "Trouble! I knew it!" exclaimed Jack to himself. "Well, I wonder what it is now. Hope word of that Klu-Klux-Klan business hasn't reached here already. But I'm not afraid of that. Even Dr. Mead will admit we acted from a right motive. All right, Martin," he called. "I'll be there as soon as I dress. Anything special?" "I'm afraid it is," replied the monitor, as he hurried down the hall. Jack made a hasty toilet and then went to the office of the head of the academy. He found a number of the teachers gathered there, including Professor Grimm, who looked more angry than usual. The latter was speaking as Jack entered: "This positively has to stop, Dr. Mead," he said. "I will put up with this no longer. Either Ranger or I must leave." "What have I done now?" asked Jack. "Something more serious than usual, Ranger, if it turns out that you are guilty," answered Dr. Mead. "Of course he's guilty," burst out Mr. Grimm. "Haven't I proof?" "Last night," said Dr. Mead, speaking slowly and sternly, "the big bell was taken from the tower. It was carried and placed in front of Professor Grimm's room, and tied to his door so that when he opened it the bell was pulled into his room. In this way some valuable sea shells he had on the floor were broken." "What makes you think I did it?" asked Jack. "I was laid up with a sprained ankle." "That's just how I know it was you and some of your chums," cried Professor Grimm. "Tied on the bell, where it had been used, so the sharp edge would not cut one's fingers, was this rag. There it is. Smell of it. What does it smell like?" and he thrust it under Jack's nose. "Why--why--it smells like arnica," replied our hero, wondering what was coming next. "Arnica! Yes, I guess it does. What was it you were pretending to put on your ankle last night, Ranger? Arnica, wasn't it? Of course it was. I've caught you this time! The evidence is all against you! You didn't think you dropped that rag, and that the arnica would figure in the evidence. Dr. Grimm, I repeat, Ranger must leave or I shall!" CHAPTER III A THREATENING LETTER For a few seconds there was a silence following Professor Grimm's ultimatum. Jack was so surprised he did not know what reply to make. The suddenness of the accusation, with the experience of the night before, and the upset over his sprained ankle, combined to make him hesitate before he made answer.