“What happened last night?” he asked.

Keith’s mind was already working swiftly.  McDowell’s question gave him the opportunity of making the first play against Shan Tung.

“Enough to convince me that I am going to see Shan Tung today,” he said.

He noticed the slow clenching and unclenching of McDowell’s fingers about the arms of his chair.

“Then—­I was right?”

“I have every reason to believe you were—­up to a certain point.  I shall know positively when I have talked with Shan Tung.”

He smiled grimly.  McDowell’s eyes were no harder than his own.  The iron man drew a deep breath and relaxed a bit in his chair.

“If anything should happen,” he said, looking away from Keith, as though the speech were merely casual, “if he attacks you—­”

“It might be necessary to kill him in self-defense,” finished Keith.

McDowell made no sign to show that he had heard, yet Keith thrilled with the conviction that he had struck home.  He went on telling briefly what had happened at Miriam Kirkstone’s house the preceding night.  McDowell’s face was purple when he described the evidences of Shan Tung’s presence at the house on the hill, but with a mighty effort he restrained his passion.

“That’s it, that’s it,” he exclaimed, choking back his wrath.  “I knew he was there!  And this morning both of them lie about it—­both of them, do you understand!  She lied, looking me straight in the eyes.  And he lied, and for the first time in his life he laughed at me, curse me if he didn’t!  It was like the gurgle of oil.  I didn’t know a human could laugh that way.  And on top of that he told me something that I won’t believe, so help me God, I won’t!”

He jumped to his feet and began pacing back and forth, his hands clenched behind him.  Suddenly he whirled on Keith.

“Why in heaven’s name didn’t you bring Keith back with you, or, if not Keith, at least a written confession, signed by him?” he demanded.

This was a blow from behind for Keith.  “What—­what has Keith got to do with this?” he stumbled.

“More than I dare tell you, Conniston.  But why didn’t you bring back a signed confession from him?  A dying man is usually willing to make that.”

“If he is guilty, yes,” agreed Keith.  “But this man was a different sort.  If he killed Judge Kirkstone, he had no regret.  He did not consider himself a criminal.  He felt that he had dealt out justice in his own way, and therefore, even when he was dying, he would not sign anything or state anything definitely.”

McDowell subsided into his chair.

“And the curse of it is I haven’t a thing on Shan Tung,” he gritted.  “Not a thing.  Miriam Kirkstone is her own mistress, and in the eyes of the law he is as innocent of crime as I am.  If she is voluntarily giving herself as a victim to this devil, it is her own business—­legally, you understand.  Morally—­”