“That’s what I’d like to know,” said Parr. “Which way did they go?” The other shook his head. “I don’t know, I can’t remember,” he said. “Is the door locked?” Jack ran to the door. The key was turned from the inside. He could not have gone that way, but the window was open. That was the first thing Parr had seen when he entered the room. He ran to the window, and looked out. There was a sheer fall of eighty feet, and no sign of a ladder or of any means by which Yale’s assailant could have escaped. “I don’t know what happened,” said Yale, when he had partially recovered. “I was sitting in this chair when suddenly a cloth was pulled across my face, and two powerful hands gripped me with a strength which I shouldn’t have thought possible in any human being. Before I could struggle or cry out I must have lost consciousness.” “Did you hear my call?” asked Parr. The other man shook his head. “But, Mr. Yale, we heard a noise and Mr. Parr asked if you were all right. You replied that you had only stumbled.” “It was not me,” said Yale. “I remember nothing from the moment the cloth was put on my face until the moment you found me here.” Inspector Parr was at the window. He pulled down the sash, and he pushed it up again, and then he looked on the window-sill, and when he turned there was a large smile on his face. “That is the cleverest thing I’ve ever seen,” he said. Something of Jack’s old antipathy to the stout detective returned. “I don’t think it is particularly clever. They’ve half-killed Yale, and they’ve got away,” he said. “I said it was clever, and it was clever,” said Mr. Parr stolidly, “and now I think I’ll go down, and interview the officers I left on duty in the hall.” But the watching officers had nothing to say. Nobody had entered or left the building except the postman. “Except the postman, eh?” said Parr thoughtfully. “Why, of course, the postman! All right, sergeant, you can dismiss your men.” He went up in the elevator and rejoined Yale. “The money’s gone all right,” he said. “I don’t know what we can do except report the matter to head-quarters.” Yale was now nearly his normal self, and sat at his desk with his head resting on his hands. “Well, I’m the culprit this time,” he said, “and they can’t blame you, Parr. I’m still trying to puzzle out how they got into that window, and how they reached me without making a sound.” “Was your back to the window?” Yale nodded. “I never dreamt of the window. I sat so that I could see both doors.” “Your back was also to the fireplace?” “They couldn’t have come that way,” said the other, shaking his head. “No, this is the supreme mystery of my career; more astounding than the identity of the Crimson Circle,” he got up slowly, “I must report this to old man Froyant, and you had better come along and lend me your moral support,” he said. “He will be furious.” They left the office together, Yale locking both doors and slipping the key into his pocket.