Detective Inspector Wessex cleared his throat and did not appear to be quite at ease.

“What is it?” inquired Nicol Brinn, and proceeded to light his cigar.

“Well, sir,” said the detective, frankly, “it’s a mighty awkward business, and I don’t know just how to approach it.”

“Shortest way,” drawled Nicol Brinn.  “Don’t study me.”

“Thanks,” said Wessex, “I’ll do my best.  It’s like this”—­he stared frankly at the impassive face:  “Where is Mr. Paul Harley?”

Nicol Brinn gazed at the lighted end of his cigar meditatively for a moment and then replaced it in the right and not in the left corner of his mouth.  Even to the trained eye of the detective inspector he seemed to be quite unmoved, but one who knew him well would have recognized that this simple action betokened suppressed excitement.

“He left these chambers at ten-fifteen on Wednesday night,” replied the American.  “I had never seen him before and I have never seen him since.”

“Sure?”

“Quite.”

“Could you swear to it before a jury?”

“You seem to doubt my word.”

Detective Inspector Wessex stood up.  “Mr. Brinn,” he said, “I am in an awkward corner.  I know you for a man with a fine sporting reputation, and therefore I don’t doubt your word.  But Mr. Paul Harley disappeared last night.”

At last Nicol Brinn was moved.  A second time he took the cigar from his mouth, gazed at the end reflectively, and then hurled the cigar across the room into the hearth.  He stood up, walked to a window, and stared out.  “Just sit quiet a minute,” came the toneless voice.  “You’ve hit me harder than you know.  I want to think it out.”

At the back of the tall, slim figure Detective Inspector Wessex stared with a sort of wonder.  Mr. Nicol Brinn of Cincinnati was a conundrum which he found himself unable to catalogue, although in his gallery of queer characters were many eccentric and peculiar.  If Nicol Brinn should prove to be crooked, then automatically he became insane.  This Wessex had reasoned out even before he had set eyes upon the celebrated American traveller.  His very first glimpse of Nicol Brinn had confirmed his reasoning, except that the cool, calm strength of the man had done much to upset the theory of lunacy.

Followed an interval of unbroken silence.  Not even the ticking of a clock could be heard in that long, singularly furnished apartment.  Then, as the detective continued to gaze upon the back of Mr. Nicol Brinn, suddenly the latter turned.

“Detective Inspector Wessex,” he said, “there has been a cloud hanging over my head for seven years.  That cloud is going to burst very soon, and it looks as if it were going to do damage.”

“I don’t understand you, sir,” replied the detective, bluntly.  “But I have been put in charge of the most extraordinary case that has ever come my way and I’ll ask you to make yourself as clear as possible.”