“555 Central: would you like to telephone to her?” said Guerchard; and he smiled triumphantly at the disabled instrument. Lupin shock his head with a careless smile, and said, “Why should I telephone to her? What are you driving at?” “Nothing ... that’s all,” said Guerchard. And he leant back in his chair with an ugly smile on his face. “Evidently nothing. For, after all, what has that child got to do with you? You’re not interested in her, plainly. She’s not big enough game for you. It’s me you are hunting ... it’s me you hate ... it’s me you want. I’ve played you tricks enough for that, you old scoundrel. So you’re going to leave that child in peace? ... You’re not going to revenge yourself on her? ... It’s all very well for you to be a policeman; it’s all very well for you to hate me; but there are things one does not do.” There was a ring of menace and appeal in the deep, ringing tones of his voice. “You’re not going to do that, Guerchard.... You will not do it.... Me—yes—anything you like. But her—her you must not touch.” He gazed at the detective with fierce, appealing eyes. “That depends on you,” said Guerchard curtly. “On me?” cried Lupin, in genuine surprise. “Yes, I’ve a little bargain to propose to you,” said Guerchard. “Have you?” said Lupin; and his watchful face was serene again, his smile almost pleasant. “Yes,” said Guerchard. And he paused, hesitating. “Well, what is it you want?” said Lupin. “Out with it! Don’t be shy about it.” “I offer you—” “You offer me?” cried Lupin. “Then it isn’t true. You’re fooling me.” “Reassure yourself,” said Guerchard coldly. “To you personally I offer nothing.” “Then you are sincere,” said Lupin. “And putting me out of the question?” “I offer you liberty.” “Who for? For my concierge?” said Lupin. “Don’t play the fool. You care only for a single person in the world. I hold you through her: Sonia Kritchnoff.” Lupin burst into a ringing, irrepressible laugh: “Why, you’re trying to blackmail me, you old sweep!” he cried. “If you like to call it so,” said Guerchard coldly. Lupin rose and walked backwards and forwards across the room, frowning, calculating, glancing keenly at Guerchard, weighing him. Twice he looked at the clock. He stopped and said coldly: “So be it. For the moment you’re the stronger.... That won’t last.... But you offer me this child’s liberty.” “That’s my offer,” said Guerchard; and his eyes brightened at the prospect of success. “Her complete liberty? ... on your word of honour?” said Lupin; and he had something of the air of a cat playing with a mouse. “On my word of honour,” said Guerchard. “Can you do it?” said Lupin, with a sudden air of doubt; and he looked sharply from Guerchard to the clock. “I undertake to do it,” said Guerchard confidently. “But how?” said Lupin, looking at him with an expression of the gravest doubt. “Oh, I’ll put the thefts on your shoulders. That will let her out all right,” said Guerchard.