There was a sudden click and the room became illuminated. Mr. Hall had pulled the chain that turned on the automatic gaslight. The two teachers were sitting up in their beds, staring at the intruders. Nat drew his bicycle pump, and Will followed his example. "Money or your life!" exclaimed Nat, in dramatic accents. "Why--why--I believe they're burglars!" cried Mr. Gales. "The impudence of them!" almost shouted Mr. Hall. The next instant he sprang out of bed and advanced on Nat and Will with long strides. This was more than the boys had bargained for. Seizing Nat, Mr. Hall, who proved much more muscular than his build indicated, fairly tossed the boy out of the window. Fortunately he fell on the soft grass and was only shaken up. "Get out of here, you scoundrel!" exclaimed the athletic teacher, making a rush for Will. "D-d-don't h-h-h-hurt me!" pleaded the bold burglar. "I-I-I-I we--" As Mr. Hall grabbed him the black mask came off and the instructor, seeing the lad's face cried out: "It's Will Slade!" He was about to send the burglar flying after his companion, but this discovery stopped him. At the same instant, the hidden crowd, thinking it was about time to do the rescue act, had started forward. "Keep back!" cried Nat. "It's a fizzle!" and he limped from under the window as fast as he could. CHAPTER IX NAT'S INVITATION The boys needed no other warning to make themselves scarce. They had reckoned without their host in planning the trick on the two teachers. "Where's Will?" asked Jack of Nat. "I guess they've caught him," the limping "burglar" said. "That means trouble," put in Sam. "How did it happen?" The conspirators were now some distance away from the Hall, and out of hearing distance. "It happened because they weren't the milksops we thought them," said Nat; rubbing his elbow. "The way he grabbed me felt as if I was being hugged by a bear." "Then they didn't get frightened?" "Not a bit. Came right at me." The boys looked back. The brilliantly lighted window of the teacher's room shone out plainly amid the blackness of the night. As the boys watched, they saw a figure climb over the sill. "There comes Will," spoke Sam. "I wonder if they're not going to report us," said Jack. "Say, It will be the first time a teacher didn't take an opportunity of getting even." As soon as Will found himself on the ground he set off on a run, toward where he supposed his friends to be in hiding. Jack gave the usual signal-whistle of his crowd, and Will, hearing it, came up quickly. "What happened?" "Didn't he make a row?" "Are they going to report it?" "How'd you get away?" These were some of the questions to which the throng of boys demanded answers. "I-I-I--c-can't t-t-tell h-h-h--." "Here! you quit that!" exclaimed Jack sternly, thinking to frighten Will out of his stuttering. The rebuke had the desired effect, and, for once Will forgot to mix his words and letters.