ng. What's the number of it?" said Lupin,
in a mocking tone.

"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.