“Now step inside, and step lively,” said the voice. “Who are you?” asked Johnson steadily. He strained his eyes to pierce the darkness, and saw the figure now. It was standing by his desk, and the shine of something in its hand warned him that the threat was no idle one. “Never met me?” There was a chuckle of laughter in the voice of the Unknown. “I’ll bet you haven’t! Friend—meet the Frog!” “The Frog?” Johnson repeated the words mechanically. “One name’s as good as another. That will do for mine,” said the stranger. “Throw over the key of your desk.” There was a silence. “I haven’t my key here,” said Johnson. “It is in the bedroom.” “Stay where you are,” warned the voice. Johnson had kicked off his slippers softly, and was feeling with his feet for the pistol he had laid so obediently on the floor in the first shock of surprise. Presently he found it and drew it toward him with his bare toes. “What do you want?” he asked, temporizing. “I want to see your office papers—all the papers you’ve brought from Maitlands.” “There is nothing here of any value,” said Johnson. The revolver was now at his feet and a little ahead of him. He kept his toes upon the butt, ready to drop just as soon as he could locate with any certainty the position of the burglar. But now, though his eyes were growing accustomed to the darkness, he could no longer see the owner of the voice. “Come nearer,” said the stranger, “and hold out your hands.” Johnson made as though to obey, but dropped suddenly to his knees. The explosion deafened him. He heard a cry, saw, in the flash of his pistol, a dark figure, and then something struck him. He came to consciousness ten minutes later, to find the room empty. Staggering to his feet, he put on the light and walked unsteadily back to his bedroom, to examine the extent of his injuries. He felt the bump on his head gingerly, and grinned. Somebody was knocking at the outer door, a peremptory, authoritative knocking. With a wet towel to his injured head he went out into the passage and opened the front door. He found two policemen at the step and a small crowd gathered on the pavement. “Has there been shooting here?” “Yes, constable,” said Johnson, “I did a little shooting, but I don’t think I hit anything.” “Have you been hurt, sir? Was it burglars?” “I can’t tell you. Come in,” said Johnson, and led the way back to the disordered library. The blind was flapping in the draught, for the window, which looked out upon a side street, was open. “Have you missed anything?” “No, I don’t think so,” said Johnson. “I think it was rather more important than an ordinary burglary. I am going to call Inspector Elk of Scotland Yard, and I think you had better leave the room as it is until he arrives.” Elk was in his office, laboriously preparing a report on the escape of Hagn, when the call came through. He listened attentively, and then: “I’ll come down, Johnson. Tell the constable to leave things—ask him to speak to me.”