“And,” said Tom, telling his father about it, “since I have promised him a large bonus if he works out that magnetic gear shift, it doesn’t seem reasonable that he would set a bomb that might destroy the results of his own hard work.” “No, Tom, it doesn’t.” “And yet I can’t help suspecting him,” mused the young inventor. “He is as friendly as ever, and seems anxious to help me. But there is something furtive in his manner and in his looks.” “Did Clark find out anything?” “Only that Greenbaum went straight to his boarding place from here and did not go out again that night. He was at home when the explosion took place.” “Then that clears him, Tom.” “No, Dad, it doesn’t. He could easily have planted a time bomb or rigged one up that was operated when I opened the door. I shall still suspect him. But I’ve got something else to do now.” “What is that?” “I want to see how Jackson is coming on with the new radio tubes he is making for the talking-picture machine and I’ve got to do something about Ned. His unexplained absence for so long a time is getting serious now. It doesn’t seem possible that he is remaining away voluntarily without sending some word.” “No, Tom, it doesn’t. What do you think?” and Mr. Swift looked up from his work. He was making some delicate tests with a galvanometer in the laboratory, which had been cleaned out and temporarily fitted up to be used again. “I’m thinking, Dad, that perhaps Ned, in some way, was concerned with the fire and explosion.” “Tom! You don’t mean that Ned——” “Oh, of course I don’t mean that he set it, Dad!” and Tom laughed at his father’s shocked face. “I mean that the same rascals who tried to blow me up kidnapped Ned.” “Kidnapped a young man like Ned Newton! A strong, husky chap——” “They may have caught him napping,” said Tom. “Anyhow, I’ve got to do something. Ned’s folks are much worried.” “Why don’t you go to the police?” “I think a private detective would be better. Or, best of all, I’ll get Clark and set out on the trail myself. I’ve got things begun on the rebuilding of my new machine now, and I’ve really got to do something about Ned.” “I agree with you, Tom. I was just wondering——” What he wondered Mr. Swift never stated, as at that moment a voice was heard out in the corridor, saying: “Bless my storage battery, you needn’t show me the way in, Eradicate! I guess I can find Tom Swift, or what’s left of him! My! My! It must have been terrible! Bless my stick of dynamite! So they tried to blow Tom up!” “It’s Mr. Damon!” said Mr. Swift, smiling at his son. “No need for him to send in a card!” chuckled the young inventor. “His voice and talk give him away. Come in, Mr. Damon!” he called, and the door opened to give entrance to the eccentric, kindly old gentleman who, indirectly, had been the means of Tom’s starting on his great inventive career.