"Mr. Durwin called in a doctor, and he says that Sir Charles had been poisoned," blurted out Penn uneasily. "I believe that woman--Mrs. Brown she called herself--poisoned him. She left the house at a quarter to nine, so the footman says, for he let her out, and----" "It is impossible that a complete stranger should poison Sir Charles," interrupted Dan impatiently, "she would not have the chance." "She was alone with Sir Charles for thirty minutes, more or less," said Penn tartly; "she had every chance and she took it." "But how could she induce Sir Charles to drink poison?" "She didn't induce him to drink anything. The doctor says that the scratch at the back of the dead man's neck----" "Here!" Dan roughly pushed the secretary aside, becoming impatient of the scrappy way in which he detailed what had happened. "Let me go to the library for myself and see what has happened. Sir Charles can't be dead." "It's twelve o'clock now," retorted Penn stepping aside, "and he's been dead quite three hours, as the doctor will tell you." Before the man finished his sentence, Dan, scarcely grasping the situation, so rapidly had it evolved, ran through the hall, towards the back of the spacious house, where the library was situated. He dashed into the large and luxuriously furnished room and collided with a police officer, who promptly took him by the shoulder. There were three other men in the room, who turned from the corpse at which they were looking, when they heard the noise of Halliday's abrupt entrance. The foremost man, and the one who spoke first, was short and stout and arrayed in uniform, with cold gray eyes, and a hard mouth. "What's this--what's this?" he demanded in a raucous voice. "Who are you?" "My name is Halliday," said Dan hurriedly. "I am engaged to Miss Moon and we have just returned from the theatre to hear--to hear----" He caught sight of Moon's body seated in the desk-chair and drooping limply over the table. "Oh, it is true, then! He is dead. Good heavens! who murdered him?" "How do you know that Sir Charles has been murdered?" asked the officer sternly. "Mr. Penn, the secretary, told me just now in the hall," said Dan, shaking himself free of the policeman. "He blurted it out like a fool, and Miss Moon has fainted. Mrs. Bolstreath has taken her upstairs. But how did it come about? Who found the body, and----" "I found the body," interrupted one of the other men, who was tall and calm-faced, with a bald head and a heavy iron-gray moustache, perfectly clothed in fashionable evening-dress, and somewhat imperious in his manner of speaking. "I had an appointment with Sir Charles at nine o'clock and came here to find him, as you now see him"--he waved his hand toward the desk--"the doctor will tell you how he died."