“Good God,” exclaimed Breese, “you almost convince me it’s so!” “I almost convince myself it’s so,” said Smith. “But I assure you----” protested Breese. “And yet,” interrupted Smith, “that doesn’t explain how he was murdered by someone unseen and unheard.” “It may have been a silencer,” I suggested. “Undoubtedly,” said Smith. “But nobody’s invented an invisible gun or an invisible man. Unless----” he stopped suddenly and looked up at the huge shrouded windows of the Gilded Cage. “Unless the executioner,” he continued grimly, “was waiting in one of those windows with a gun and silencer.” He shouted suddenly. “That’s it.” He pointed to one of the windows. “No doubt of it,” he continued excitedly. “A man standing there, at that window--Spence down here in the cab and----” To our amazement the window swung open. Then we saw a huge head. Perutkin appeared at the window. He was beckoning to Smith, suggesting by signs that he go into the house. “There’s that lunatic again,” muttered Breese. “What’s he doing here?” Smith demanded of me. “I’ll have to lock him up just to get rid of him.” But the Russian was gesticulating wildly. “He wants us to come in,” I suggested. “I want to go in anyway,” said Smith, moving up the long stairs to the terrace. “He’s probably got another hare-brained scheme.” He dismissed the Russian from his mind contemptuously. “But that’s the explanation. No doubt of it. Spence was killed from a window in this house. Now we’ll find out who’s in that house and this time I let nobody go.” “But who can it be?” muttered Breese. “Someone I know? Someone in the house, someone with us on the yacht? The mere thought of it is appalling.” We had reached the terrace. The door swung open. The Russian greeted us. “A thousand pardons, Mr. Smith,” he called. “I left you unceremoniously. I plead haste. And a thousand pardons to you, Mr. Breese. I am responsible for any unpleasantness that may have been caused you. I was led astray. I insisted you were a criminal. And I had no evidence. I can only beg your pardon.” “What is it you want now?” Smith insisted grimly. “You’ve got nothing more to do with this case. You know that, don’t you?” “That is true,” replied the Russian, “in half an hour I shall have nothing more to do with this case. Yours shall be the glory, Mr. Smith. The case is over.” He paused. “It is too bad about Spence. A blackmailer, but still a human being.” “How do you know about him?” Smith demanded. “I foresaw his end, poor chap,” the Russian sighed. “When I left you so hurriedly I had hoped to prevent it. But when I came here I knew I was too late.” Smith looked at him, shaking his head in baffled wonder.