“Do you know, Seton,” he said, “you are the one man in London whose company I could have tolerated tonight.”

“My arrival was peculiarly opportune.”

“Your arrivals are always peculiarly opportune.”  Gray stared at Seton with an expression of puzzled admiration.  “I don’t think I shall ever understand your turning up immediately before the Senussi raid in Egypt.  Do you remember?  I was with the armored cars.”

“I remember perfectly.”

“Then you vanished in the same mysterious fashion, and the C. O. was a sphinx on the subject.  I next saw you strolling out of the gate at Baghdad.  How the devil you’d got to Baghdad, considering that you didn’t come with us and that you weren’t with the cavalry, heaven only knows!”

“No,” said Seton judicially, gazing through his uplifted wine-glass; “when one comes to consider the matter without prejudice it is certainly odd.  But do I know the lady to whose non-appearance I owe the pleasure of your company tonight?”

Quentin Gray stared at him blankly.

“Really, Seton, you amaze me.  Did I say that I had an appointment with a lady?”

“My dear Gray, when I see a man standing biting his nails and glaring out into Piccadilly from a restaurant entrance I ask myself a question.  When I learn that he has just cancelled an order for a table for two I answer it.”

Gray laughed.  “You always make me feel so infernally young, Seton.”

“Good!”

“Yes, it’s good to feel young, but bad to feel a young fool; and that’s what I feel—­and what I am.  Listen!”

Leaning across the table so that the light of the shaded lamp fell fully upon his flushed, eager face, Gray, not without embarrassment, told his companion of the “dirty trick”—­so he phrased it—­which Sir Lucien Pyne had played upon him.  In conclusion: 

“What would you do, Seton?” he asked.

Seton sat regarding him in silence with a cool, calculating stare which some men had termed insolent, absently tapping his teeth with the gold rim of a monocle which he carried but apparently never used for any other purpose; and it was at about this time that a long low car passed near the door of the restaurant, crossing the traffic stream of Piccadilly to draw up at the corner of old Bond Street.

From the car Monte Irvin alighted and, telling the man to wait, set out on foot.  Ten paces along Bond Street he encountered a small, stooping figure which became detached from the shadows of a shop door.  The light of a street lamp shone down upon the sharp, hooked nose and into the cunning little brown eyes of Brisley, of Spinker’s Detective Agency.  Monte Irvin started.

“Ah, Brisley!” he said, “I was looking for you.  Are they still there?”

“Probably, sir.”  Brisley licked his lips.  “My colleague, Gunn, reports no one came out whilst I was away ’phoning.”

“But the whole thing seems preposterous.  Are there no other offices in the block where they might be?”