On returning to his office Paul Harley found awaiting him the report of the man to whom he had entrusted the study of the movements of Nicol Brinn. His mood was a disturbed one, and he had observed none of his customary precautions in coming from Doctor McMurdoch’s house. He wondered if the surveillance which he had once detected had ceased. Perhaps the chambers of Nicol Brinn were the true danger zone upon which these subtle but powerful forces now were focussed. On the other hand, he was quite well aware that his movements might have been watched almost uninterruptedly since the hour that Sir Charles Abingdon had visited his office.  
During the previous day, in his attempt to learn the identity of Ormuz Khan, he had covered his tracks with his customary care. He had sufficient faith in his knowledge of disguise, which was extensive, to believe that those mysterious persons who were interested in his movements remained unaware of the fact that the simple-minded visitor from Vancouver who had spent several hours in and about the Savoy, and Paul Harley of Chancery Lane, were one and the same.
 
His brain was far too alertly engaged with troubled thoughts of Phil Abingdon to be susceptible to the influence of those delicate etheric waves which he had come to recognize as the note of danger. Practically there had been no development whatever in the investigation, and he was almost tempted to believe that the whole thing was a mirage, when the sight of the typewritten report translated him mentally to the luxurious chambers in Piccadilly.
 
Again, almost clairvoyantly, he saw the stoical American seated before the empty fireplace, his foot restlessly tapping the fender. Again he heard the curious, high tones: “I’ll tell you... You have opened the gates of hell....”
 
The whole scene, with its tantalizing undercurrent of mystery, was reenacted before his inner vision. He seemed to hear Nicol Brinn, startled from his reverie, exclaim: “I think it was an owl.... We sometimes get them over from the Green Park....”
 
Why should so simple an incident have produced so singular an effect? For the face of the speaker had been ashen.
 
Then the pendulum swung inevitably back: “You are all perfectly cruel and horrible....”
 
Paul Harley clenched his hands, frowning at the Burmese cabinet as though he hated it.
 
How persistently the voice of Phil Abingdon rang in his ears! He could not forget her lightest words. How hopelessly her bewitching image intruded itself between his reasoning mind and the problem upon which he sought to concentrate.
 
Miss Smith, the typist, had gone, for it was after six o’clock, and Innes alone was on duty. He came in as Harley, placing his hat and cane upon the big writing table, sat down to study the report.
 
“Inspector Wessex rang up, Mr. Harley, about an hour ago. He said he would be at the Yard until six.”
 
“Has he obtained any information?” asked Paul Harley, wearily, glancing at his little table clock.
 
“He said he had had insufficient time to do much in the matter, but that there were one or two outstanding facts which might interest you.”
 
“Did he seem to be surprised?”
 
“He did,” confessed Innes. “He said that Ormuz Khan was a well-known figure in financial circles, and asked me in what way you were interested in him.”
 
“Ah!” murmured Harley. He took up the telephone. “City 400,” he said.... “Is that the Commissioner’s Office, New Scotland Yard? ... Paul Harley speaking. Would you please inquire if Detective Inspector Wessex has gone?”
 
While awaiting a reply he looked up at Innes. “Is there anything else?” he asked.
 
“Only the letters, Mr. Harley.”
 
“No callers?”
 
“No.”
 
“Leave the letters, then; I will see to them. You need not wait.” A moment later, as his secretary bade him good-night and went out of the office:
 
“Hello,” said Harley, speaking into the mouthpiece... “The inspector has gone? Perhaps you would ask him to ring me up in the morning.” He replaced the receiver on the hook.
 
Resting his chin in his hands, he began to read from the typewritten pages before him. His assistant’s report was conceived as follows:
 
‘Re Mr. Nicol Brinn of Raleigh House, Piccadilly, W. I.
 
‘Mr. Nicol Brinn is an American citizen, born at Cincinnati, Ohio, February 15, 1884. He is the son of John Nicolas Brinn of the same city, founder of the firm of J. Nicolas Brinn, Incorporated, later reconstituted under the style of Brinn’s Universal Electric Supply Corporation.
 
‘Nicol Brinn is a graduate of Harvard. He has travelled extensively in nearly all parts of the world and has access to the best society of Europe and America. He has a reputation for eccentricity, has won numerous sporting events as a gentleman rider; was the first airman to fly over the Rockies; took part in the Uruguay rebellion of 1904, and held the rank of lieutenant colonel of field artillery with the American forces during the Great War.
 
‘He has published a work on big game and has contributed numerous travel articles to American periodicals. On the death of Mr. Brinn, senior, in 1914, he inherited an e............