But nothing was found that would indicate in any way what had happened to the youthful inventor. The men who had used the secret flight of steps and the tunnel to carry Tom away had returned soon after overpowering him and had covered the opening to the underground stairs, scattering earth and débris over the planks so that a casual examination would disclose nothing wrong. A closer inspection might have disclosed signs of fresh earth scattered about, but this kind of examination was not made. By this time every one connected with the Swift factory knew of the young inventor’s disappearance, and work was ordered stopped for a time while a minute search was begun. Tom was looked for in all possible and in some impossible places, but all to no effect. The day passed. Mary remained at the Swift house in order to be close at hand if Tom should return unexpectedly. Ned began to look and feel blue and depressed when night came again and there was no sign of Tom. But, in contrast to this, Mary was outwardly more cheerful. “Somehow,” she said, “I feel that we shall have news of Tom before morning.” “What makes you think so?” asked Ned. “I don’t know—but I have that feeling,” answered the girl. “You know if Tom has been caught and taken away, night would be the best time for him to escape, wouldn’t it?” “Yes, it would,” admitted Ned. “But I can’t believe that he has been captured.” “I can,” Mary asserted. “I have had a feeling for some time that Tom would be in danger as soon as he tried to go ahead with that new invention of his—the airline express. It always has happened so from the time he made his first speedy motor boat until he put his valuable papers in the Chest of Secrets. Always some enemies have been on his trail. And you don’t imagine they’re going to stop and let him alone, do you, when he’s got something as big as this airline express almost perfected?” “Well, of course there are always scoundrels ready to take advantage of what an inventor does,” admitted Ned. “But this airline express has been kept so secret I thought only a few of us knew of it.” “That’s what Tom hoped,” Mary said. “But only a few days ago he told me he had had to discharge two men because he suspected them. I forget their names—something like Renny and Hemp.” “Kenny and Schlump,” corrected Ned. “Yes, he told me about those men. But still, and with all you have said, I can’t believe Tom has been captured.” The day passed and night came. Mr. Swift remained at the private office in the plant until nearly ten o’clock, hoping that some word would come from Tom; but none did, and an hour later Mr. Damon insisted on taking the old inventor home. “Koku and I will stay here,” volunteered Ned. “And, after all, Tom is as likely to go home or send some word there as he is to come to the plant. So we can divide our forces.”