“Hadn’t you better look at that note before you go up?” suggested Ned, motioning to the pocket in which Tom had put the letter the boy had delivered to him at the last minute. “That’s so—I almost forgot about it,” said the young inventor, with a laugh. “But it’s too late to answer it—we’re quite a way from the starting point.” This was true. It had taken only a few minutes for them to soar over New York City, with its forest of tall buildings, then over the Hudson, across Jersey City, and so out on the long straight air line that led to Chicago. Tom pulled out the crumpled missive and ripped open the envelope. As he read the few lines a look of anger came over his face. “What is it?” asked Ned. “Read it yourself,” Tom answered. And Ned scanned these lines: “Look out for yourself. You have started but you haven’t finished. Our time is coming. “The Masked Two.” “Well, of all the nerve!” cried Ned. “Haven’t they!” said Tom. “But it will take more than threats to make me give up this project. I haven’t got my final patent papers, but I will when I finish these trial trips. I need to make only five more after this, and then Jacks will put in a lot of money. It was lack of ready money that was holding me back—once I have plenty of cash I can snap my fingers at those fellows!” “Only five more trips,” murmured Ned. “And this one hasn’t finished its first third, Tom. But we’ll do it! The Masked Two can go jump in the lake.” “You said it!” exclaimed Tom. “I’m not going to worry any more about it. Come on up in the plane with me.” But though Tom declared that he was not going to worry over the matter, still he could not altogether dismiss it from his mind. He had left his aged father at home in charge of the works, and though there were faithful men around him and every safeguard that ingenuity could devise, still those sinister enemies might find some way of breaking through the cordon and damaging the plant or injuring Mr. Swift. So, in spite of his brave words, Tom worried. “However, we’re in touch with them all the while by wireless,” Ned remarked, as Meldrum and Dodge descended when Tom had assumed charge of the controls, with Ned to help him. “You can always send and receive messages, and so you’ll know when anything happens.” “Yes,” agreed the young inventor. “I almost forgot about that. I can keep in touch with home that way. I’ll wireless back soon, and see how everything is.” This Tom did after he had speeded up the plane a little, once he found the motor was working well after warming up. They were now high in the air, hastening west. Ned sent off the message through the ether waves. A powerful radio set had been installed, and Tom could talk directly to his father, which he was soon doing. “We’re making fast time, Dad,” he told him. “How are things back there?” “All right, Tom. You made a fine start. I only hope you keep it up.”