Phil and Tom soon found themselves in the midst of a number of choice spirits, who moved silently about the lower end of the corridor, near a room that was sometimes used for student meetings, and where, more than once, it was whispered, smokers had been held, in violation of the rules. The reason for the selection of this apartment was that it had an open fireplace, which carried off the fumes of the tobacco. "Did he get the tip?" asked Jerry, as he and his brother, together with Phil and Tom, came up. "He sure did," answered Bricktop. "Reports from the front are that he is on the warpath." "Is everything working all right?" asked Joe. "Fine. Can't you smell it?" Tom and Phil sniffed the air. There was an unmistakable odor of tobacco. "But if there's a smoker going on in there, why was Pitchfork tipped off?" inquired Tom. "Wait an' ye'll see, me lad," advised Bricktop in his rich brogue. "I think he's coming now. Pump her up, Kindlings!" Then, for the first time Tom and his chum noticed that Dan Woodhouse had a small air pump, which he was vigorously working, as he stood in a dark corner. Footsteps sounded down the corridor. There were hasty cautions from the ringleaders, and the lads hid themselves in the dim shadows of the big hall. The footsteps came nearer, and then they seemed to cease. But the reason was soon apparent, for Professor Emerson Tines was now tip-toeing his way toward the door of the suspected room. By the dim light of a half-turned down gas jet he could be seen sneaking up. The only sound from the students was the faint sound of the air pump. Tom and Phil could not imagine what it was for. Professor Tines reached the portal. Then he gave a sudden knock, and called: "I demand to be admitted at once, young gentlemen! I know the nefarious practice that is going on in there, and it must stop at once! Open the door or I shall summon the janitor and have it forced! Open at once!" The professor tried the knob. To his surprise it at once opened the door, and he almost stumbled into the apartment. He uttered an exclamation of delight, probably in the belief that he had caught the students red-handed, but the next moment he gave a gasp of dismay.