"Then why do you stay?"

"For a very good reason, Petrie, and the same that prompts me to retain the Tûlun-Nûr box in my own possession rather than to deposit it in the strong-room of my bank."

"I begin to understand."

"I trust you do, Petrie; it is fairly obvious. Probably the plan is a perilous one, but I hope, by laying myself open to attack, to apprehend the enemy—perhaps to make an important capture."

Setting down my glass, I stared in silence at Smith.

"I will anticipate your remark," he said, smiling dryly. "I am aware that I am not entitled to expose you to these dangers. It is my duty and I must perform it as best I can; you, as a volunteer, are perfectly entitled to withdraw."

As I continued silently to stare at him, his expression changed; the gray eyes grew less steely, and presently, clapping his hand upon my shoulder in his impulsive way—

"Petrie!" he cried, "you know I had no intention of hurting your feelings, but in the circumstances it was impossible for me to say less."

"You have said enough, Smith," I replied shortly. "I beg of you to say no more."

He gripped my shoulder hard, then plunged his hand into his pocket and pulled out the blackened pipe.