“If I were a writing man, which, thank heavens, I am not,” he said, “I should carry this story of the Trasmere murder, the ‘Mystery of the Three Keys.’ Here is one solved, and it wasn’t much of a mystery. There are two others. The third is the most difficult of all.” “You mean the key that was found on the table in the vault?” He nodded. “Yes,” he said, and said no more. In her discretion, Ursula asked no further questions. Tab was looking at Carver with a new respect. “Every day, Carver,” he said seriously, “you are getting nearer the fictional ideal of a real detective!” Carver’s down-turned lips took an upward curve, and then he looked at his watch. “Ten o’clock, Miss Ardfern,” he said with mock severity, and Ursula made a move to the door. “We must turn these lights out before you leave the room. Everything must be done in order, remembering that somewhere the Black Man is watching.” She shivered. It was Tab who blew out the light in the drawing-room. “I think we may draw the curtains,” said Carver softly, and pulled back the heavy velvet hangings from the window. It was a starlight night and there was just sufficient light in the sky to outline the gateway. “This will do admirably,” he said, settling himself in the window-seat. “If you must smoke, Tab, don’t bring your pipe within sight of that gate.” Tab groaned and laid his pipe upon the fender. Ten minutes later Ursula came into the room. “May I stay?” she whispered. “I have put out my bedroom light most artistically.” They conversed in whispers for an hour, and Tab was beginning to feel sleepy when a hiss from Carver stopped him in the middle of a sentence. Looking out of the window he saw a dark figure by the gate. It was impossible to distinguish more than the outlines. It appeared to be a man of considerable height, but this might have been and probably was an illusion. It wore a broad-brimmed hat, presumably dark; more than this they could not see. They waited in silence as the gate opened and the figure stole noiselessly into the garden. It was half-way to the door when another figure appeared. It came from nowhere, seeming to rise up from the ground; and then before the man in the wide-awake hat could draw back, the second man had flung himself upon him. The watchers sat paralyzed until Carter, jumping to his feet, ran out of the room, Tab close behind him. When they flung open the door, both figures had disappeared. Carver sprang toward the gate and stumbled. His foot had struck a soft bulk which stretched across the garden path, he turned back, flashing an electric lamp upon the object. It was a man, and for a moment they did not see his face. “Who are you?” Carver pulled the man over on his back. “Well, I’m--” The man at his feet was Yeh Ling! XVIII