"I'll have to ride in to Mansburg for some," he decided. "I'll go after supper, on my motor-cycle, and test the battery to-night." The young inventor left his house immediately after the evening meal. Along the road toward Mansburg he speeded, and, as he came to the foot of a hill, where once Andy Foger had put a big tree, hoping Tom would run into it and be injured, the youth recalled that circumstance. "Andy has been keeping out of my way lately," mused Tom. "I wonder if he's up to any mischief? I don't like the way Sam Snedecker is hanging around the shop, either. It looks as if they were plotting something. But I guess Eradicate and his pail of whitewash will scare them off." Tom got the powdered chemical he wanted in the drug store, and, after refreshing himself with some ice cream soda, he started back. As he rode along through the streets of the town he kept a lookout, and those of you who know how fond the lad was of a certain young lady, do not need to be told for whom he was looking. But he did not see her, and soon turned into the main highway leading to Shopton. It was dark when he reached the hill, where once he had been so near an accident, and he slowed up as he coasted down it, using the brake at intervals. Tom got safely to the bottom of the declivity, and was about to turn on the power of his machine, when, from the bushes that lined either side of the roadway, several figures sprang suddenly. They ranged themselves across the road, and one cried: "Halt!" in tones that were meant to be stern, but which seemed to Tom, to tremble somewhat. The young inventor was so surprised that he did not open the gasolene throttle, nor switch on his spark. As a consequence his motor-cycle lost momentum, and he had to take one foot from the pedal and touch the ground, to prevent himself from toppling over. "Hold on there!" cried another voice. "We've got you where we want you, now! Hold on! Don't go!" "I wasn't going to go," responded Tom calmly, trying to recognize the voice, which seemed to be unnatural. "What do you want, and who are you?" "Never mind who we are. We want you and we've got you! Get off that wheel!" "I don't see why I should!" exclaimed Tom, and he suddenly shifted his handle bars, so as to flash the bright headlight he carried, upon the circle of dark figures that opposed his progress. As the light flashed on them he was surprised to see that all the figures wore masks over their faces. Tom started. Was this the Happy Harry gang after him again? He hoped not, yet the fact that the persons had on masks made the hold-up have an ugly look. Once more Tom flashed the light on the throng. There were exclamations of dismay. "Douse that glim, somebody!" called a sharp voice, which Tom could not recognize.