"B, the second letter in the alphabet, stands for 2," he whispers excitedly. "The last words written by Samuel Boyd on the memorandum which would send his son to the gallows if it were found, were 'Notation 2647.' The sixth letter in the alphabet is F." He presses the letter, and the figure 6 appears on the knob. "Ha, ha! The fourth letter, D." He presses that, and the figure 4 appears, the figures now ranging 264. "The seventh letter, G. The notation is complete--2647!" Such perfect control did the speaker have over himself that even in that moment of excitement his voice does not rise above a whisper. Both men are now in a standing posture, the discoverer of the simple cryptogram holding the cane. "Now for the test," he says, and with the ball of his broad thumb he presses hard upon the four figures. A click is heard. The silver knob springs up. "The jewels!" he whispers, exultantly. "They are here--they are here! See!" In the utterance of the word a vivid flash of lightning illumines the room, and one man utters a startled exclamation, the other a frenzied shriek, for in that momentary flash they see the figure of the Chinaman rise suddenly from its chair. The candle is dashed to the ground, enveloping them in black darkness, and the cane, with its concealed treasure, is plucked from the hand that held it! CHAPTER LIX. CONSTABLE APPLEBEE DISTINGUISHES HIMSELF. Constable Applebee, seeking shelter from the storm beneath the roof of Deadman's Court, kept his face and his thoughts in the direction of Samuel Boyd's house, for such complete possession had the mystery taken of him that lightning, wind, and rain were powerless to drive it from his mind. Besides which, as he afterwards informed his wife, he had a presentiment that "something was going to happen." The latest flash of lightning caused him to clap his hand instinctively upon his eyes; the crash of thunder that followed caused him to drop his hand. Then, as though the elements had exhausted themselves, there was a sudden hush, for the sound of the fast-falling rain was faint in his ears after the deafening thunderpeal. So faint, indeed, that, in the belief that the storm was spent, he stepped into Catchpole Square and looked around, distinguishing only the outlines of the buildings because of the darkness of the night. Almost on the instant the door of Samuel Boyd's house was violently opened, and a man rushed out, slamming it behind him. With such frantic haste did he run that he came into collision with the constable, and both were nearly upset. They recovered their equilibrium simultaneously, and before the man could get his breath Applebee proved himself equal to the occasion. "Easy, there!" he exclaimed, and with one hand caught the man by the throat, while with the other he raised his whistle to his lips, and blew a loud and vigorous summons for assistance.