Had Wu Fang Chien reasoned along similar lines? It was natural that the Chinese authorities had not wanted the American to visit one of the isolated leper colonies. Wu Fang Chien had discovered Gray's mission. And the mandarin had been willing to kill Gray in order to keep him from Sungan. The Asiatic had tried to keep the white man from probing into one of the hidden, infected spots of Mongolia. Was this the truth? Gray, heart-sick from what Hastings had told him, believed so. Later, he came to understand more fully the motives that had actuated Wu Fang Chien. "Remember," continued Sir Lionel wearily, "we learned that the Wusun were captives. The stone itself--the boundary stone we found at Ansichow--said as much." "But the stone referred to the Wusun as conquerors." "Some legend of a former century. Another of the riddles--of Asia. I'm afraid, Captain Gray, we've failed in our mission. And it has cost--much." He coughed, and raised his eyes to Gray. "We have found the lepers of Sungan. And we have let them take Mary. I'm out of the game, rather. And I'd prefer to die here than in a mule litter. You've done all for me you can." Gray made a gesture of denial. The pluck of the Englishman, facing inevitable death, stirred his admiration. Lack of vitality, more than the wound, made it impossible to get Hastings out of the Gobi alive. Knowing this, Sir Lionel treated his own situation as indifferently as he might have disposed of a routine question of drill. "I didn't tell you about the lepers at first," he continued, "because I was afraid you might lack the nerve to go on. I wouldn't blame you. But I've seen you under fire--and I know better." "I'm going after Mary," said Gray grimly. Sir Lionel nodded. "Of course. Not much of a chance; but--I'm glad." He coughed and wiped his lips. "You were right, Captain Gray. She--she told me what you said at Ansichow. I regret that she--offended you. I have spoiled her, you know. A dear girl----" His cough silenced him. Gray sought for words, and was silent. Neither man liked to reveal his feelings. "My heedlessness brought Mary to Sungan, Captain Gray. Now I'm asking you to make good my mistake, if possible----" "Excellency!" The shaggy head of Mirai Khan appeared between the tent flaps. "I must speak with you." Gray went outside, to find the Kirghiz scowling and ill at ease. In their faces the sun was vanishing over the plain of the Gobi, dyeing the bare, yellow hillocks with deep crimson. A brown lizard trailed its body away from the two men, leaving the mark of its passage in the sand. "Excellency, the hour of our parting is at hand. I go no further. The debt I owed you for saving my life I still owe, but--you will not turn back from Sungan. Hearken, hunter of the mighty little gun. I and my comrades followed the tracks of our enemies. They were camel tracks." "Nonsense," growled Gray. "Those were men with guns. You saw them."