Before Mr. Kimball started for his home, renewed thanks had been made to the farmer and his son for the part they had played in the rescue, and the young inventor, learning that the boy had a liking for things mechanical, promised to aid him in his intention to become a machinist. "But first get a good education," Tom advised. "Keep on with your school work, and when the time comes I'll take you into my shop." "And maybe he'll make a tank that will rival yours, Tom," said Ned. "Maybe he will! I hope he does. If he comes along fast enough, he can help with something else I'm going to start soon." "Whats that?" asked Mr. Damon. "Oh, it's something on the same order, designed to help batter down the German lines," Tom answered. "I haven't quite made up my mind what to call it yet. But let's get home. I want to see that my tank is safe. The absence of the plotters from the factory makes me suspicious." On the way back Tom told more of the details of the attack. "But we'll forget about it all, now you're out," remarked Ned. "And the sooner we get home, the better," added Tom. "Can't you get a little more speed out of this machine?" he asked. "Well, it isn't the Hawk," replied Ned, "but we'll see what we can do," and he made the runabout fairly fly. Mrs. Baggert was the first to greet Tom as they arrived at his home. She did not seem as surprised as either Tom, Ned or Mr. Damon expected her to be. "Well, I'm glad you're all right," she said. "And it's a good thing you sent that note, for your father was so excited and worried I was getting apprehensive about him." "What note?" asked Tom, while a queer look came into his face. "Why, the one you sent saying you were detained on business and would probably not be home for a week, and to have Koku and the men bring the tank to you." "Bring the tank! A note from me!" exclaimed Tom. "The plotters again! And they've got the tank!" He ran to the big shop followed by the others. Throwing open the doors, they went inside. A glance sufficed to disclose the worst. The place where the great tank had stood was empty. "Gone!" gasped Tom. Chapter XXIV Camouflaged Two utterances Tom Swift made when the fact of the disappearance of the tank became known to him were characteristic of the young inventor. The first was: "How did they get it away?" And the second was: "Come on, let's get after 'em!" Then, for a few moments, no one said anything. Tom, Ned, and Mr. Damon, with Mrs. Baggert in the background, stood looking at the great empty machine shop. "Well, they got her," went on Tom, with a sigh. "I was afraid of this as soon as they left me alone at the factory." "Is anything wrong?" faltered the housekeeper. "Didn't you send for the tank, Tom?" "No, Mrs. Baggert, I didn't," Tom answered.