"I don't know about that, sir," answered the chauffeur, while the gardener merely shrugged his shoulders. He was an old man and one who had been trusted by the Morrs for years. "If what you say is true, I'll have to look into this matter," remarked Senator Morr. "I don't propose to have my garage burnt down, with two automobiles worth five thousand dollars,--not to say anything about the danger to the rest of the place. If I find----" Bang! It was an explosion like a cannon and made everybody jump. As Dave looked, he saw a corner of a distant fence fly apart, and bits of fire seemed to fill the midnight air. Then followed utter silence. [Illustration: AS DAVE LOOKED, HE SAW A CORNER OF A DISTANT FENCE FLY APART.] "The cannon cracker!" gasped Phil. "What could have made it go off?" asked Roger. "Some sparks from this fire--or else it was lit when Phil took it out," answered Dave. "What are you talking about?" asked Senator Morr, and when he had been told he shook his head and smiled, grimly. "Well, I'm glad it didn't go off in the garage," he said. "But after this you must keep your explosives in a safer place. Jake, James, bring some buckets of water and put out that fire from the explosion. It isn't much, but we want no more sparks flying around here." The water was brought, and soon every spark had been extinguished. Then the crowd went back to the garage, to make sure that no more fire lingered in that vicinity. "It certainly looks as if somebody had set this fire," mused Senator Morr. "Perhaps a tramp. Have you seen any such fellows around here?" he asked, looking at the others. The boys had seen no tramps at all, and James said he had seen none for over a week. "I saw one day before yesterday," said the chauffeur, "but I know he left town that night--I saw him board a freight train." "Well, it is strange. Keep your eyes open," said Senator Morr, and then he returned to the house, to quiet his wife and retire once more. "It's mighty queer about that fire," remarked Luke, when the boys were undressing. "It certainly does look as if it was set." "Dave, do you think Merwell and Haskers would do it?" questioned Roger. "Yes, if they were in this neighborhood. But have they been here?" The boys looked at each other. Nobody had seen Merwell or the former teacher of Oak Hall in that vicinity. "Let us make some inquiries down at the railroad station in the morning," suggested Dave. "If those two stopped off here somebody must have seen them." "Phew! what a noise that cannon cracker did make!" murmured Phil. "If we had set that off in the morning--as we intended--I reckon it would have woke up the neighborhood pretty well." "It did wake some folks up," answered Roger, for quite a few boys and men had come up to find out what the flames and noise meant. "It was certainly some firecracker," was Luke's comment. "Say, speaking of firecrackers puts me in mind of a story!" burst out Shadow.