She writhed in his clasp, uttered a half-stifled cry, and wrenching one arm free, tried to thrust him away. Then Jack came in. He covered the course in four running strides, stooped, seized Da Cunha around the neck, and jerked him on to his feet. Whereon followed--catastrophe. Jack slipped on the polished floor, stumbled, tried to recover--and fell. Da Cunha twisted about and kicked him above the left temple. He lay prone. “Jack!” cried Nanette. “Jack!” O’Shea’s grip on my wrist was like a vise. “Wait,” he said. “The boy’s down but he’s not out!” O’Shea was right. Nanette’s voice recalled him. Da Cunha wore only light dancing shoes. Jack rolled over, avoided a second swinging kick, and came to his feet, shaking his tawny head like a terrier with a flea in his ear. “Jack!” cried Nanette again. She crouched on the divan, wide-eyed. Her shoulder strap had slipped; and Nanette will never know how beautiful I know she is. Even as I saw, guiltily, she readjusted it--and the fight started. Blood was trickling into Jack’s eyes. He kept dodging and trying to clear his sight. It upset his judgment, beyond a doubt; added to which his skull must have been humming like a beehive. Remember, too, the climb he had put in. To my intense annoyance, the none-such proved able to box as well as he danced and kicked. He took all a trained fighter’s advantage of Jack’s double handicap. Some punishment came his way, but it was not heavy--and he kept registering killing body blows on his opponent. Jack might have planted a lucky one before it was too late. But Nanette defeated him. “Jack!” she cried, a sob in her voice. “Don’t let him _beat_ you!” Half-dazed, the boy paused, dropped his hands--and Da Cunha recorded a tremendous right well below the belt. Jack went down--to stay. “The dirty swine!” I exclaimed. O’Shea slipped a revolver into my hand. “I don’t think there are any servants about to-night,” he said. “But see that I’m not interrupted.” He stepped in through the open window, twirling his monocle on its black ribbon. It was not pose; it was nerves. The man was human. He was fighting for composure. Da Cunha faced him, and: “_You!_” came, as a sort of rapturous sigh, from the divan. The two men confronted each other for an electric moment; then: “You are a very dirty fighter, Da Cunha,” said O’Shea smoothly. “But, as you are probably tired, I suggest that you give me the black dispatch-box that you have locked in your bedroom--and we will say no more about it.” Da Cunha’s expression became complicated. My own brain was revolving like a merry-go-round. This sudden revelation was too much for me--that Da Cunha was a Red agent! “Go to hell!” was the reply. “Who are you?” “You are very forgetful,” said O’Shea.