"No, sah, dat's whut he can't do!" insisted the colored man. "Why not?" asked Tom. "'Cause Boomerang's on guard, an' yo'-all knows how dat mule of mine can use his heels!" "I know, Rad," went on Tom; "but this fellow will find a way of keeping out of their way. We must hurry." "Oh, he's safe enough," declared the colored man. "I done tole Koku to stan' guard, too! Dat low-down white trash ob a giant is all right fo' guardin', but he ain't wuff shucks at detectin'!" said Eradicate, with pardonable pride. "By golly, maybe I's too old t' put on guard, but I kin detect, all right!" "If this proves true, I'll begin to believe you can," replied Tom. "Hop along, Ned!" Followed by the shuffling and chuckling negro, Tom and Ned went to the rather insecure stable where the mule Boomerang was kept. That is, the stable was insecure from the standpoint of a jail. But the sight of the giant Koku marching up and down in front of the place, armed with a big club, reassured Tom. "Is he in there, Koku?" asked the young inventor. "Yes, Master! He try once come out, but he approach his head very close my defense weapon and he go back again." "I should think he would," laughed Ned, as he noted the giant's club. "Well, Rad, let's have a look at your prisoner. Open the door, Koku," commanded Tom. "Better look out," advised Ned. "He may be armed." "We'll have to take a chance. Besides, I don't believe he is, or he'd have fired at Koku. There isn't much to fear with the giant ready for emergencies. Now we'll see who he is. I can't imagine one of my men turning traitor." The door was opened and a rather miserable-looking man shuffled out. There was a bloody rag on his head, and he seemed to have made more of an effort to escape than Koku described, for he appeared to have suffered in the ensuing fight. "Carl Schwen!" exclaimed Tom. "So it was you, was it?" The German, for such he was, did not answer for a moment. He appeared downcast, and as if suffering. Then a change came over him. He straightened up, saluted as a soldier might have done, and a sneering look came into his face. It was succeeded by one of pride as the man exclaimed: "Yes, it is I! And I tried to do what I tried to do for the Fatherland! I have failed. Now you will have me shot as a spy, I suppose!" he added bitterly. Tom did not answer directly. He looked keenly at the man, and at last said: "I am sorry to see this. I knew you were a German, Schwen, but I kept you employed at work that could not, by any possibility, be considered as used against your country. You are a good machinist, and I needed you. But if what I hear about you is true, it is the end." "It is the end," said the man simply. "I tried and failed. If it had not been for Eradicate--Well, he's smarter than I gave him credit for, that's all!" The man spoke very good English, with hardly a trace of German accent, but there was no doubt as to his character. "What will you do with him, Tom?" asked Ned.