But trouble for Dave was not yet at an end. One of the teachers at Oak Hall was Job Haskers, a learned man, but one who did not like boys. Why Haskers had ever become an instructor was a mystery. He was harsh, unsympathetic, and dictatorial, and nearly all the students hated him. He knew the branches he taught, but that was all the good that could be said of him. Trouble came almost from the start, that term, and not only Dave, but nearly all of his chums were involved. A wild man--who afterwards proved to be related to Nat Poole, the son of a miserly money-lender of Crumville--tried to blow up a neighboring hotel, and the boys were thought to be guilty. In terror, some of them feared arrest and fled, as related in "Dave Porter and the Runaways." Dave went after the runaways, and after escaping a fearful flood, made them come back to school and face the music. The youth had a clew against Job Haskers, and in the end proved that the wild man was guilty and that the instructor knew it. This news came as a thunder-clap to Doctor Clay, the owner of the school, and without ceremony he called Haskers before him and demanded his resignation. At first the dictatorial teacher would not resign, but when confronted by the proofs of his duplicity, he got out in a hurry; and all the other teachers, and the students, were glad of it. "And now for a grand wind-up!" Dave had said, and then he and his chums had settled down to work, and later on, graduated from Oak Hall with high honors. At the graduation exercises, Dave was one of the happiest boys in the school. His family and Jessie and several others came to the affair, which was celebrated with numerous bonfires, and music by a band, and refreshments in the gymnasium. "And now what are you going to do?" Laura had asked, of her brother. "First of all, he is going to pay me a visit," Roger had said. "I have been to your house half a dozen times and Dave has hardly been to our place at all. He is to come, and so are Phil and some of the others. My mother wants them, and so does my dad." "Well, if the others are to be there, I'll have to come, too," Dave had replied; and so it had been settled, and that is how we now find the boys at Senator Morr's fine country mansion, located on the outskirts of the village of Hemson. Dave and Phil had been there for four days, and Roger and his parents had done all in their power to make the visitors feel at home. "Here is some more news that I overlooked," said Roger, as he turned over one of his letters. "This is from a chum of mine, Bert Passmore, who is spending his summer at Lake Sargola, about thirty miles from here. He says they are going to have a special concert to-morrow afternoon and evening, given by a well-known military band from Washington. He says we had better come over and take it in." "I shouldn't mind taking in a concert like that," replied Phil. "I like good brass-band music better than anything else." "How about you, Dave?"