“It will not begin to show itself until Monday or Tuesday,” was the confident answer. “And even then the symptoms will be inconclusive. There aren’t half a dozen physicians who would know what they meant in any of the early stages, and by the time any one could authoritatively diagnose the case, the patient would be beyond help. In fact, he’ll be beyond it for all ordinary purposes from the time the serum is introduced into his system, and before the twenty-seventh he’ll be dead.” CHAPTER XX. QUICK WORK IS NECESSARY. “Dead!” The way in which Stone repeated the word gave a hint to the listener of the grim hatred that possessed that demented brain. There was a moment’s silence, then Follansbee’s voice came again. “Above all, however,” he said, “remember that you must not be in a hurry. Do everything deliberately and don’t get rattled for a moment. There’s nothing to fear if you keep your nerve. Finally, don’t attempt to carry out your—operations shall we call it?—until half past two.” “Why should we wait? Why couldn’t we do it now?” Stone urged. “If you were a medical man you would know why,” Follansbee answered in his squeaking voice. “Between two and three o’clock in the morning human life is at its lowest ebb. The flame of vitality burns more dimly then than at any time during the twenty-four hours. That’s the answer, and its application to this case ought to be apparent enough.” Nick heard a movement, as though Doctor Follansbee had leaned forward in his chair to drive his point home. “You have waited months for this, Stone,” the peculiar voice went on, “and an hour more or less can’t make any difference. Crawford will be in a sound sleep at half past two, if he’s as normal as he seems to be, and the low vitality which is natural at that hour will make him an easy subject to handle; in other words, you will have the best chance of successfully drugging him.” The chair creaked again. “You’re going now?” asked the miner. “Yes. It’s much better that I should. My continued presence would tempt us to talk, and we might disturb the man in the next room. You don’t want to do that, you know. You want to find him as helpless as possible when the time comes, so I’d advise you to keep as still as you can. Don’t pace the room, or anything like that.” “But I’m nervous as a cat,” objected Stone. “Who wouldn’t be?” “I suppose you are,” Follansbee admitted, “but—here’s something to quiet you. It will give you new courage, too. Just deposit this powder on the end of your tongue and wash it down with a little water.” There was a pause, and the detective suspected that the miner was staring questionably at Follansbee. Stone’s next words confirmed it. “You’re sure about this?” the man asked slowly. “It won’t hurt me or keep me from doing what I’ve sworn to do?”