“Not this time, Clark,” answered Tom, motioning the young fellow to take a chair near the scorched desk which was not far from the shattered talking-picture machine. That apparatus had, however, been covered from prying eyes. “I want you to do a bit of detective work, if you will,” went on the young inventor. Without telling just why he wanted the information, Tom instructed his agent to find out in secret something about Greenbaum, seeking to learn just what the man did on the night of the explosion. “I get you!” exclaimed Clark, with ready wit. “I’m wise all right. I’ll shadow him if you want me to.” “No, don’t dog him,” objected Tom. “Just trace his movements. You can tell your foreman you’re working for me and it will be all right.” With Clark dispatched on this mission, Tom took from the partial wreck of his new apparatus such pieces as were vital for rebuilding it and then, asking his father to have the laboratory cleaned up and put in working shape again, Tom went back to his bedroom. Truth to tell, he was pretty well fagged out, not so much physically as mentally. The shock both to his hopes and his body, as well as worry over Ned’s disappearance, was beginning to tell. “Hadn’t you better give this up, Tom?” asked his father as, having set men to putting the laboratory to rights, he went to his son’s room where he found Tom stretched out on a long sofa. “Give what up, Dad? You mean trying to find out who blew me up and why Ned is missing? Give those problems up?” “No, I mean work on this new talking-picture machine of yours. I don’t believe it will ever work, Tom.” “But it has worked, Dad!” exclaimed the young man, with enthusiasm. “Only about an hour before Ned left and the explosion happened, I got a pretty fine record of what Ned did in the theater room,” for so Tom called the apartment with its battery of bright lights where the young manager had sung and danced. “You heard Ned’s voice?” asked Mr. Swift. “Perfectly,” declared Tom. “Saw him, too. But the vision was not as clear as it’s got to be to make this a commercial success. But I know how to improve it, and I’m going to. I can’t give that up, Dad!” “It might be better if you did, Tom.” “Better? How?” “Well, for your own safety. You’re using powerful electrical currents and you’ve had one explosion already; so——” “But didn’t I tell you, Dad,” and Tom smiled tolerantly, “that this explosion was none of my doing? Nothing went wrong with the wires. They were all in shape and I was just opening the door when something went off. It was something that was set, too—a bomb, if I guess aright.” “All the more reason for giving it up, Tom.” “What do you mean, Dad?”