“You hound!”

The duke would have taken the stranger by the throat, and have done his best to choke the life right out of him then and there, if Mr. Dacre had not intervened.

“Steady, old man!” Mr. Dacre turned to the stranger.  “You appear to be a pretty sort of a scoundrel.”

The stranger gave his shoulders that almost imperceptible shrug.

“Oh, my dear Dacre, I am in want of money!  I believe that you sometimes are in want of money, too.”

Everybody knows that nobody knows where Ivor Dacre gets his money from, so the allusion must have tickled him immensely.

“You’re a cool hand,” he said.

“Some men are born that way.”

“So I should imagine.  Men like you must be born, not made.”

“Precisely—­as you say!” The stranger turned, with his graceful smile, to the duke:  “But are we not wasting precious time?  I can assure your grace that, in this particular matter, moments are of value.”

Mr. Dacre interposed before the duke could answer.

“If you take my strongly urged advice, Datchet, you will summon this constable who is now coming down the Arcade, and hand this gentleman over to his keeping.  I do not think that you need fear that the duchess will lose her arm, or even her little finger.  Scoundrels of this one’s kidney are most amenable to reason when they have handcuffs on their wrists.”

The duke plainly hesitated.  He would—­and he would not.  The stranger, as he eyed him, seemed much amused.

“My dear duke, by all means act on Mr. Dacre’s valuable suggestion.  As I said before, why not?  It would at least be interesting to see if the duchess does or does not lose her arm—­almost as interesting to you as to Mr. Dacre.  Those blackmailing, kidnaping scoundrels do use such empty menaces.  Besides, you would have the pleasure of seeing me locked up.  My imprisonment for life would recompense you even for the loss of her grace’s arm.  And five hundred pounds is such a sum to have to pay—­merely for a wife!  Why not, therefore, act on Mr. Dacre’s suggestion?  Here comes the constable.”  The constable referred to was advancing toward them—­he was not a dozen yards away.  “Let me beckon to him—­I will with pleasure.”  He took out his watch—­a gold chronograph repeater.  “There are scarcely ten minutes left during which it will be possible for me to send the communication which I spoke of, so that it may arrive in time.  As it will then be too late, and the instruments are already prepared for the little operation which her grace is eagerly anticipating, it would, perhaps, be as well, after all, that you should give me into charge.  You would have saved your five hundred pounds, and you would, at any rate, have something in exchange for her grace’s mutilated limb.  Ah, here is the constable!  Officer!”

The stranger spoke with such a pleasant little air of easy geniality that it was impossible to tell if he were in jest or in earnest.  This fact impressed the duke much more than if he had gone in for a liberal indulgence of the—­under the circumstances—­orthodox melodramatic scowling.  And, indeed, in the face of his own common sense, it impressed Mr. Ivor Dacre too.