“I know it now,” declared the Scotsman, solemnly.  “Abingdon was always eccentric, but he didn’t know the meaning of fear.”

“Once that may have been true,” replied Harley.  “But a great fear was upon him when he came to me, Doctor McMurdoch, and if it is humanly possible I am going to discover its cause.”

“Go ahead,” said Doctor McMurdoch and, turning to the side table, he poured out two liberal portions of whiskey.  “If there’s anything I can do to help, count me at your service.  You tell me he had fears about little Phil?”

“He had,” answered Harley, “and it is maddening to think that he died before he could acquaint me with their nature.  But I have hopes that you can help me in this.  For instance”—­again he fixed his gaze upon the gloomy face of the physician—­“who is the distinguished Oriental gentleman with whom Sir Charles had recently become acquainted?”

Doctor McMurdoch’s expression remained utterly blank, and he slowly shook his head.  “I haven’t an idea in the world,” he declared.  “A patient, perhaps?”

“Possibly,” said Harley, conscious of some disappointment; “yet from the way he spoke of him I scarcely think that he was a patient.  Surely Sir Charles, having resided so long in India, numbered several Orientals among his acquaintances if not among his friends?”

“None ever came to his home,” replied Doctor McMurdoch.  “He had all the Anglo-Indian’s prejudice against men of colour.”  He rested his massive chin in his hand and stared down reflectively at the carpet.

“Then you have no suggestion to offer in regard to this person?”

“None.  Did he tell you nothing further about him?”

“Unfortunately, nothing.  In the next place, Doctor McMurdoch, are you aware of any difference of opinion which had arisen latterly between Sir Charles and his daughter?”

“Difference of opinion!” replied Doctor McMurdoch, raising his brows ironically.  “There would always be difference of opinion between little Phil and any man who cared for her.  But out-and-out quarrel—­no!”

Again Harley found himself at a deadlock, and it was with scanty hope of success that he put his third question to the gloomy Scot.  “Was Sir Charles a friend of Mr. Nicol Brinn?” he asked.

“Nicol Brinn?” echoed the physician.  He looked perplexed.  “You mean the American millionaire?  I believe they were acquainted.  Abingdon knew most of the extraordinary people in London; and if half one hears is true Nicol Brinn is as mad as a hatter.  But they were not in any sense friends as far as I know.”  He was watching Harley curiously.  “Why do you ask that question?”

“I will tell you in a moment,” said Harley, rapidly, “but I have one more question to put to you first.  Does the term Fire-Tongue convey anything to your mind?”

Doctor McMurdoch’s eyebrows shot upward most amazingly.  “I won’t insult you by supposing that you have chosen such a time for joking,” he said, dourly.  “But if your third question surprised me, I must say that your fourth sounds simply daft.”