“Your threats haven’t any weight with me, Follansbee,” the detective answered quietly. “I’ve devoted my life to handling such blackguards as you. You’re clever, but you’re not clever enough; no scamp is. The evil he does trips him up sooner or later. I tell you here and now that you will not enjoy one penny of that money, no matter what happens. You may spend some of it, but you’ll be looking for a thunderbolt all the time.” As he spoke, he half turned and approached the door. He took good care, however, to keep one eye on the physician, for he knew that at that moment Follansbee was ready for anything. “I’ve given you your chance,” the detective said, as he laid his hand on the knob, “and you haven’t seen fit to take it. I can find Stone without aid, and when I do, you’ll discover that you’ve made a bad bargain. Good afternoon.” The door closed behind the lithe figure, and Follansbee just for a moment allowed his stiff attitude to relax. It seemed as though the lean body shrank, that his clothes suddenly became too large for him. There was a curious mummylike expression about his sharp features as he leaned against the mantel. “How much does he know?” he muttered to himself. “By heavens, it was well that I got rid of Stone when I did. I defy him to find out where he is now.” A sudden gust of anger swept over him, and he reeled toward the door, shaking his fists. “I defy you! I defy you!” he shrieked, in his thin voice. “Look out for yourself, Nick Carter! Men have died for less than you have done.” There was an unholy meaning in his voice, and the face looked fiendish in its menace. At that moment Stephen Follansbee looked what he was—an insatiable bird of prey. “Only let me get you into my power,” he continued, “and nothing in the world will save you!” Nick Carter had made another enemy; one whose scientific resources and unusual shrewdness might have daunted almost any one, when coupled, as they were, with the maddening thirst for revenge which shook him at that moment. CHAPTER XXXIX. PATSY TRACES THE AMBULANCE. There is always a certain element of luck in one’s experiences, and chance ordained it that Patsy Garvan should arrive in front of St. Swithin’s Hospital at just the right moment. His anxiety had sent him in that direction after his repeated failures to reach his chief, but he had no very definite idea in view.