"I've got it," he announced. Then, turning towards the silent figure on his right, he added almost mockingly, "Quite a dramatic moment, isn't it, de Roda?" I heard the sharp click of the lock, and almost simultaneously a flood of light streamed out through the doorway. With a strange gasping sob de Roda thrust his companion aside, and, trampling on my foot as he passed, stumbled blindly ahead of us into the hall. Manning shrugged his shoulders. "You must make allowances for the old gentleman, Dryden," he said. "He has been very hardly treated, and I'm afraid it's affected his manners." He stepped forward, laughing quietly to himself, and, without waiting for further orders, Craill dragged me roughly in after him and closed the door behind us. "I think that end of the room will be a good place for our host," observed Manning, pointing towards the staircase. "You can tie him up comfortably there, and then he will be able to get a nice uninterrupted view of our researches." Powerless to resist; I was hauled to my feet and lashed securely with my back to the banisters--a proceeding which gave me such pain in my injured shoulder that I had all my work cut out to remain silent. With a cruel smile upon his lips Manning stood watching the operation. One side of his face was still bruised and swelled almost out of recognition, and even in the midst of my own suffering the sight filled me with fierce and exulting pleasure. "You are not looking quite at your best, Manning," I remarked, "I am afraid you must have had another sleepless night." "Shall I give 'im a wipe across the mouth?" growled Craill. "That'll stop his jaw." Manning silenced him with a gesture. "I don't think I shall be very much in your debt by the time I have finished with you, Dryden," he replied pleasantly. A queer exclamation from de Roda, who was crouching in front of the fireplace, broke in suddenly upon our conversation. "You were right," he cried hoarsely, "you were right, doctor! It is here! I see it myself." He pointed with trembling fingers towards a small ornamental knob in the centre of the grate, which I had noticed on several occasions bore a rough resemblance to a bull-dog's head. Manning glanced round unconcernedly, and then turned back to me. "You must excuse me for a moment," he said. "Mr. de Roda is naturally impatient." He walked across to the hearth, and the gaunt, huddled figure of the other moved aside to make room for him. "Now we shall see," he remarked. "It will be very disappointing if I am wrong after all." He caught the knob in both hands, and, bending forwards, gave it a sharp wrench. Instantly, and without the least noise, the whole front of one of the side pillars swung open like a door, exposing a high narrow cavity lined with brick. In a second de Roda had flung himself on his knees and was groping in the aperture. "They are here!" he screamed wildly. "My God, they are here!"