David Guinness jerked around, as did his daughter. The man who had spoken stood only ten yards away, clearly outlined in the bright moonlight--a tall, well-built man, standing quite at ease, surveying them pleasantly. His smile did not change when old Guinness cried: "Quade! James Quade!" The man nodded and came slowly forward. He might have been considered handsome, had it not been for his thin, mocking lips and a swarthy complexion. "What are you doing here?" demanded Guinness angrily. "And what do you mean--'it was a gun?' Have you--" "Easy, easy--one thing at a time," said Quade, still smiling. "About the gun--well, your young friend Holmes said, he'd be right back, but I--I'm afraid he won't be." * * * * * Sue Guinness's lips formed a frightened word: "Why?" Quade made a short movement with his left hand, as is brushing the query aside. "Let's talk about something more pleasant," he said, and looked back at the professor. "The radium, and your borer, for instance. I hear you're all ready to go down." David Guinness gasped. "How did you know--?" he began, but a surge of anger choked him, and his fists clenched. He stepped forward. But something came to life in James Quade's right hand and pointed menacingly at him. It was the stubby black shape of an automatic. "Keep back, you old fool!" Quade said harshly. "I don't want to have to shoot you!" Unwillingly, Guinness came to a stop. "What have you done with young Holmes?" he demanded. "Never mind about him now," said Quade, smiling again. "Perhaps I'll explain later. At the moment there's something much more interesting to do. Possibly you'll be surprised to hear it, but we're all going to take a little ride in this machine of yours, Professor. Down. About four miles. I'll have to ask you to do the driving. You will, won't you--without making a fuss?" Guinness's face worked furiously. "Why, you're crazy, Quade!" he sputtered. "I certainly won't!" "No?" asked Quade softly. The automatic he held veered around, till it was pointing directly at the girl. "I wouldn't want to have to shoot Sue--say--through the hand...." His finger tightened perceptibly on the trigger. "You're mad, man!" Guinness burst out. "You're crazy! What's the idea--" "In due time I'll tell you. But now I'll ask you just once more," Quade persisted. "Will you enter that borer, or must I--" He broke off with an expressive shrug. David Guinness was powerless. He had not the slightest idea what Quade might be about; the one thought that broke through his fear and anger was that the man was mad, and had better be humored. He trembled, and a tight sensation came to his throat at sight of the steady gun trained on his daughter. He dared not trifle. "I'll do it," he said. * * * * *