From somewhere above us--I could not determine the exact direction--came a low, wailing cry, an uncanny thing of falling cadences, which, in that dismal vault, with the sinister yellow-robed figure at the door, seemed to pour ice into my veins. Its effect upon Smith was truly extraordinary. His face showed grayly in the faint light, and I heard him draw a hissing breath through clenched teeth. "It calls for you!" said Fu-Manchu. "At half-past twelve it calls for Graham Guthrie!" The door closed and darkness mantled us again. "Smith," I said, "what was that?" The horrors about us were playing havoc with my nerves. "It was the Call of Siva!" replied Smith hoarsely. "What is it? Who uttered it? What does it mean?" "I don't know what it is, Petrie, nor who utters it. But it means death!" CHAPTER XIV THERE may be some who could have lain, chained to that noisome cell, and felt no fear--no dread of what the blackness might hold. I confess that I am not one of these. I knew that Nayland Smith and I stood in the path of the most stupendous genius who in the world's history had devoted his intellect to crime. I knew that the enormous wealth of the political group backing Dr. Fu-Manchu rendered him a menace to Europe and to America greater than that of the plague. He was a scientist trained at a great university--an explorer of nature's secrets, who had gone farther into the unknown, I suppose, than any living man. His mission was to remove all obstacles--human obstacles--from the path of that secret movement which was progressing in the Far East. Smith and I were two such obstacles; and of all the horrible devices at his command, I wondered, and my tortured brain refused to leave the subject, by which of them were we doomed to be dispatched? Even at that very moment some venomous centipede might be wriggling towards me over the slime of the stones, some poisonous spider be preparing to drop from the roof! Fu-Manchu might have released a serpent in the cellar, or the air be alive with microbes of a loathsome disease! "Smith," I said, scarcely recognizing my own voice, "I can't bear this suspense. He intends to kill us, that is certain, but--" "Don't worry," came the reply; "he intends to learn our plans first." "You mean--?" "You heard him speak of his files and of his wire jacket?" "Oh, my God!" I groaned; "can this be England?" Smith laughed dryly, and I heard him fumbling with the steel collar about his neck. "I have one great hope," he said, "since you share my captivity, but we must neglect no minor chance. Try with your pocket-knife if you can force the lock. I am trying to break this one." Truth to tell, the idea had not entered my half-dazed mind, but I immediately acted upon my friend's suggestion, setting to work with the small blade of my knife. I was so engaged, and, having snapped one blade, was about to open another, when a sound arrested me. It came from beneath my feet.