There was a brief silence.  Norgate glanced around the room.

“I don’t see Mrs. Benedek here this afternoon,” he remarked.

Selingman shook his head solemnly.

“The inquest on the death of that poor fellow Baring is being held to-day,” he explained.  “That is why she is staying away.  A sad thing that, Norgate—­a very sad happening.”

“It was indeed.”

“And mysterious,” Selingman went on.  “The man apparently, an hour before, was in high spirits.  The special work upon which he was engaged at the Admiralty was almost finished.  He had received high praise for his share in it.  Every one who had seen him that day spoke of him as in absolutely capital form.  Suddenly he whips out a revolver from his desk and shoots himself, and all that any one knows is that he was rung up by some one on the telephone.  There’s a puzzle for you, Norgate.”

Norgate made no reply.  He felt Selingman’s eyes upon him.

“A wonderful plot for the sensational novelist.  To the ordinary human being who knew Baring, there remains a substratum almost of uneasiness.  Where did that voice come from that spoke along the wires, and what was its message?  Baring, by all accounts, had no secrets in his life.  What was the message—­a warning or a threat?”

“I did not read the account of the inquest,” Norgate observed.  “Wasn’t it possible to trace the person who rang up, through the telephone office?”

“In an ordinary case, yes,” Selingman agreed.  “In this case, no!  The person who rang up made use of a call office.  But come, it is a gloomy subject, this.  I wish I had known that you were likely to see Mr. Hebblethwaite this afternoon.  Bear this in mind in case you should come across him again.  It would interest me very much to know whether any breach of friendship has taken place at all between him and Mr. Spencer Wyatt.  Do you know Spencer Wyatt, by-the-by?”

“Only slightly,” Norgate replied, “Not well enough to talk to him intimately, as I can do to Hebblethwaite.”

“Well, remember that last little commission,” Selingman concluded.  “Are you staying on or leaving now?  If you are going, we will walk together.  A little exercise is good for me sometimes.  My figure requires it.  It is a very short distance, but it is better than nothing at all.”

“I am quite ready,” Norgate assured him.

They left the room and descended the stairs together.  At the entrance to the building, Selingman paused for a moment.  Then he seemed suddenly to remember.

“It is habit,” he declared.  “I stand here for a taxi, but we have agreed to walk, is it not so?  Come!”

Norgate was looking across the street to the other side of the pavement.  A man was standing there, engaged in conversation with a plainly-dressed young woman.  To Norgate there was something vaguely familiar about the latter, who turned to glance at him as they strolled by on the other side of the road.  It was not until they reached the corner of the street, however, that he remembered.  She was the young woman at the telephone call office near Westbourne Grove!