In the afternoon, about six hours before the time set, Tom was in his workroom putting some finishing touches to the machinery and testing the electrical wires when he heard Eradicate coming along the corridor. Something in the colored man’s step and the fact that he was muttering excitedly to himself, roused Tom’s curiosity and fears. “What’s the matter, Rad?” he asked, opening the door in response to the faithful black man’s knock. “Man jest give me dis,” answered Eradicate, holding out a letter. “Where did you get it?” “Out in de yard,” was the answer. “I was walkin’ round like yo’ done tole me watchin’ fo’ strangers, when de man come up an’ handed me dis. He were a stranger—I was goin’ to tell him to make his se’f skurse when he done hand me dat.” Eradicate nodded toward the note which Tom held. “Did he say anything when he gave it to you?” asked Tom. “He say ‘gib dat to Tom Swift. It may be life or death to him,’” quoted Eradicate. Tom hastily tore open the envelope. As he read the message a cry of rage and astonishment came to his lips. CHAPTER XVI A STARTLING DISCOVERY “WHAT’S the matter?” asked Ned Newton. He had been making the broadcasting studio ready for the performance he and Mr. Damon would soon give in there, so Tom could show his assembled party of guests what the new invention would do. “What’s wrong, Tom?” he asked again, entering the laboratory just as his chum finished reading the sinister message that Eradicate had handed him. “Wrong is the word,” murmured Tom, again reading the warning. “What do you think of that?” and he handed the paper to his financial manager. Ned scanned the scrawl—it was only that—words hastily scribbled on a piece of wrapping paper and enclosed in a dirty envelope. “Whew!” whistled Ned as he read. And this is what his eyes took in: “Tom Swift: If you exhibit your new talking pictures your whole plant will be blown to atoms. Take warning in time.” “There’s no name signed to it,” remarked Ned. “There doesn’t need be,” responded his chum. “It’s easy to guess that this comes from the same crowd who kidnapped you and me—the same men who tried to blow me up. There’s no need for a name.” “No, I guess you’re right,” Ned agreed. “Still, if we could trace these fellows——” “Oh, I’m going to try!” exclaimed Tom. “I’m not going to sit idly down and let them think they have us scared. Eradicate, show me just where you met this man and tell me what he looked like.” The negro did his best, but he was getting old and his memory was not what it had been. He gave a rather hazy description of the bearer of the sinister warning, but he was able to point out the place where he had come upon the intruder. Intruder was exactly what the messenger was, for, since beginning work on his latest invention, Tom had taken precautions to admit none but his own men to the plant.