For, as Tom, Phil, and all the others could see from their vantage points in the shadowy recesses, the room was empty. It was lighted, however, and in plain view on a table in the middle of the floor was a large flask. In the top of this there was a receptacle which contained a pile of burning tobacco, and it was glowing as though some giant was puffing on the improvised pipe. From a glass tube extending from the flask there poured out volumes of the pungent odor, and, as the puffs came, Tom and Phil could hear the air pump being worked. It was a "studentless smoker," the air pump, attached to a rubber hose which exhausted the air from the flask, producing exactly the effect of some one puffing a pipe. The room was blue with the haze of tobacco, and as the astonished professor stood and gazed at the strange sight more smoke arose from the flask. Then, from somewhere in the dark recesses of the corridor came a voice. "Stung!" it ejaculated, and there was a hurried movement as the students fled in the darkness. CHAPTER VIII THE ENVELOPE Plunging on through the darkened corridors Tom and Phil reached their room. They found Sid still on the sofa. "Say, that was great!" cried Tom, venturing to laugh, now that there was no danger of being caught. "You should have been along, Sid. Pitchfork got his to-night, all right. I'll never forget the blank look on his face." "I either," agreed Phil. "That was a smoker as was a smoker. I hope none of us are caught. The twins and Bricktop outdid themselves this trip." Sid began to show some signs of interest, and the trick was told of in detail to him. Of course a faculty inquiry followed, but the hose and air pump had been taken from the school laboratory, and there were no clues to the perpetrators. Professor Tines was furious, and demanded that the guilty ones be dismissed. "Willingly, my dear professor," agreed the venerable Dr. Churchill, "if I can only find them," and there was a twinkle in his deep-set eyes, which he took care that Mr. Tines did not see. Baseball practice went on for several days. One afternoon, as the lads were dispersing, Ed Kerr was seen coming over the diamond, holding in his hand a letter. "We can't play Fairview Saturday," he announced. "Why not?" asked Tom quickly. "They say they're not quite ready to open their season," went on the manager. "They ask me to put the opening game off a week." "Are you going to do it?" inquired several. "Well, what do you fellows say?" asked the manager. "Oh, well, they probably have a good reason. We'll let it go a week," assented Tom. "But can we get another game in place of it?" "Yes, I can fill in with the Layton Preparatory school for this Saturday, and we can go to Wescott University the following Saturday, and then tackle Fairview, if you fellows say so." "Sure," came in a chorus. When Tom and Phil returned to their room Sid was not there.