“I hope I haven’t kept you waiting.”

The voice which interrupted Mr. Dacre came from the rear.  While they were looking in front of them some one approached them from behind, apparently coming out of the shop which was at their backs.

The speaker looked a gentleman.  He sounded like one, too.  Costume, appearance, manner, were beyond reproach—­even beyond the criticism of two such keen critics as were these.  The glorious attire of a London dandy was surmounted with a beautiful white top hat.  In his buttonhole was a magnificent gardenia.

In age the stranger was scarcely more than a boy, and a sunny-faced, handsome boy at that.  His cheeks were hairless, his eyes were blue.  His smile was not only innocent, it was bland.  Never was there a more conspicuous illustration of that repose which stamps the caste of Vere de Vere.

The duke looked at him and glowered.  Mr. Dacre looked at him and smiled.

“Who are you?” asked the duke.

“Ah—­that is the question!” The newcomer’s refined and musical voice breathed the very soul of affability.  “I am an individual who is so unfortunate as to be in want of five hundred pounds.”

“Are you the scoundrel who sent me that infamous letter?”

The charming stranger never turned a hair.

“I am the scoundrel mentioned in that infamous letter who wants to accost you at the Piccadilly end of the Burlington Arcade before half-past five—­as witness my white hat and my gardenia.”

“Where’s my wife?”

The stranger gently swung his stick in front of him with his two hands.  He regarded the duke as a merry-hearted son might regard his father.  The thing was beautiful!

“Her grace will be home almost as soon as you are—­when you have given me the money which I perceive you have all ready for me in that scarcely elegant-looking canvas bag.”  He shrugged his shoulders quite gracefully.  “Unfortunately, in these matters one has no choice—­one is forced to ask for gold.”

“And suppose, instead of giving you what is in this canvas bag, I take you by the throat and choke the life right out of you?”

“Or suppose,” amended Mr. Dacre, “that you do better, and commend this gentleman to the tender mercies of the first policeman we encounter.”

The stranger turned to Mr. Dacre.  He condescended to become conscious of his presence.

“Is this gentleman your grace’s friend?  Ah—­Mr. Dacre, I perceive!  I have the honor of knowing Mr. Dacre, though, possibly, I am unknown to him.”

“You were—­until this moment.”

With an airy little laugh the stranger returned to the duke.  He brushed an invisible speck of dust off the sleeve of his coat.

“As has been intimated in that infamous letter, his grace is at perfect liberty to give me into custody—­why not?  Only”—­he said it with his boyish smile—­“if a particular communication is not received from me in certain quarters within a certain time the Duchess of Datchet’s beautiful white arm will be hacked off at the shoulder.”