He rang the bell communicating with the outer office.  Innes came in.  “Innes,” he said, rapidly, “is there anything of really first-rate importance with which I should deal personally?”

“Well,” replied the secretary, glancing at some papers which he carried, “there is nothing that could not wait until to-morrow at a pinch.”

“The pinch has come,” said Harley.  “I am going to interview the two most important witnesses in the Abingdon case.”

“To whom do you refer, Mr. Harley?”

Innes stared rather blankly, as he made the inquiry, whereupon: 

“I have no time to explain,” continued Harley.  “But I have suddenly realized the importance of a seemingly trivial incident which I witnessed.  It is these trivial incidents, Innes, which so often contain the hidden clue.”

“What! you really think you have a clue at last?”

“I do.”  The speaker’s face grew grimly serious.  “Innes, if I am right, I shall probably proceed to one of two places:  the apartments of Ormuz Khan or the chambers of Nicol Brinn.  Listen.  Remain here until I phone—­whatever the hour.”

“Shall I advise Wessex to stand by?”

Harley nodded.  “Yes—­do so.  You understand, Innes, I am engaged and not to be disturbed on any account?”

“I understand.  You are going out by the private exit?”

“Exactly.”

As Innes retired, quietly closing the door, Harley took up the telephone and called Sir Charles Abingdon’s number.  He was answered by a voice which he recognized.

“This is Paul Harley speaking,” he said.  “Is that Benson?”

“Yes, sir,” answered the butler.  “Good morning, sir.”

“Good morning, Benson.  I have one or two questions to ask you, and there is something I want you to do for me.  Miss Abingdon is out, I presume?”

“Yes, sir,” replied Benson, sadly.  “At the funeral, sir.”

“Is Mrs. Howett in?”

“She is, sir.”

“I shall be around in about a quarter of an hour, Benson.  In the meantime, will you be good enough to lay the dining table exactly as it was laid on the night of Sir Charles’s death?”

Benson could be heard nervously clearing his throat, then:  “Perhaps, sir,” he said, diffidently, “I didn’t quite understand you.  Lay the table, sir, for dinner?”

“For dinner—­exactly.  I want everything to be there that was present on the night of the tragedy; everything.  Naturally you will have to place different flowers in the vases, but I want to see the same vases.  From the soup tureen to the serviette rings, Benson, I wish you to duplicate the dinner table as I remember it, paying particular attention to the exact position of each article.  Mrs. Howett will doubtless be able to assist you in this.”

“Very good, sir,” said Benson—­but his voice betokened bewilderment.  “I will see Mrs. Howett at once, sir.”

“Right.  Good-bye.”