Seton glanced inquiringly at his wife, and she nodded, smiling.

“Right-o!” he said.  “If you will excuse me for a moment I will get my notes.  Hello, here’s Gray!”

A little two-seater came bowling along the road from Cairo, and drew up beneath the balcony.  It was the car which had belonged to Margaret when in practice in Dover Street.  Quentin Gray jumped out, waving his hand cheerily to the quartette above, and went in at the doorway.  Seton walked through the flat and admitted him.

“Sorry I’m late!” cried Gray, impetuous and boyish as ever, although he looked older and had grown very bronzed.  “The chief detained me.”

“Go through to them,” said Seton informally.  “I’m getting my notes; we’re going to read the thrilling story of the Kazmah mystery before dinner.”

“Good enough!” cried Gray.  “I’m in the dark on many points.”

He had outlived his youthful infatuation, although it was probable enough that had Rita been free he would have presented himself as a suitor without delay.  But the old relationship he had no desire to renew.  A generous self-effacing regard had supplanted the madness of his earlier passion.  Rita had changed too; she had learned to know herself and to know her husband.

So that when Seton Pasha presently rejoined his guests, he found the most complete harmony to prevail among them.  He carried a bulky notebook, and, tapping his teeth with his monocle: 

“Ladies and gentlemen,” he began whimsically, “I will bore you with a brief account of the extraordinary facts concerning the Kazmah case.”

Margaret was seated in the rest-chair which her husband had vacated, and Seton took up a position upon the ledge formed by one of the wide arms.  Everyone prepared to listen, with interest undisguised.

“There were three outstanding personalities dominating what we may term the Kazmah group,” continued Seton.  “In order of importance they were:  Sin Sin Wa, Sir Lucien Pyne and Mrs. Sin.”

Rita Irvin inhaled deeply, but did not interrupt the speaker.

“I shall begin with Sir Lucien,” Seton went on.  “For some years before his father’s death he seems to have lived a very shady life in many parts of the world.  He was a confirmed gambler, and was also somewhat unduly fond of the ladies’ society.  In Buenos Ayres—­the exact date does not matter—­he made the acquaintance of a variety artiste known as La Belle Lola, a Cuban-Jewess, good-looking and unscrupulous.  I cannot say if Sir Lucien was aware from the outset of his affair with La Belle that she was a married woman.  But it is certain that her husband, Sin Sin Wa, very early learned of the intrigue, and condoned it.

“How Sir Lucien came to get into the clutches of the pair I do not know.  But that he did so we have ascertained beyond doubt.  I think, personally, that his third vice—­opium—­was probably responsible.  For Sin Sin Wa appears throughout in the character of a drug dealer.