“Quite so,” nodded Mr. Carlyle, as his host paused.

“You see the whole sequence, of course?”

“Not exactly—­not in detail,” confessed Mr. Carlyle.

“Dompierre’s idea was to gain access to some of the most celebrated cabinets of Europe and substitute Stelli’s fabrications for the genuine coins.  The princely collection of rarities that he would thus amass might be difficult to dispose of safely, but I have no doubt that he had matured his plans.  Helene, in the person of Nina Brun, an Anglicised French parlourmaid—­a part which she fills to perfection—­was to obtain wax impressions of the most valuable pieces and to make the exchange when the counterfeits reached her.  In this way it was obviously hoped that the fraud would not come to light until long after the real coins had been sold, and I gather that she has already done her work successfully in general houses.  Then, impressed by her excellent references and capable manner, my housekeeper engaged her, and for a few weeks she went about her duties here.  It was fatal to this detail of the scheme, however, that I have the misfortune to be blind.  I am told that Helene has so innocently angelic a face as to disarm suspicion, but I was incapable of being impressed and that good material was thrown away.  But one morning my material fingers—­which, of course, knew nothing of Helene’s angelic face—­discovered an unfamiliar touch about the surface of my favourite Euclideas, and, although there was doubtless nothing to be seen, my critical sense of smell reported that wax had been recently pressed against it.  I began to make discreet inquiries and in the meantime my cabinets went to the local bank for safety.  Helene countered by receiving a telegram from Angiers, calling her to the death-bed of her aged mother.  The aged mother succumbed; duty compelled Helene to remain at the side of her stricken patriarchal father, and doubtless The Turrets was written off the syndicate’s operations as a bad debt.”

“Very interesting,” admitted Mr. Carlyle; “but at the risk of seeming obtuse”—­his manner had become delicately chastened—­“I must say that I fail to trace the inevitable connexion between Nina Brun and this particular forgery—­assuming that it is a forgery.”

“Set your mind at rest about that, Louis,” replied Carrados.  “It is a forgery, and it is a forgery that none but Pietro Stelli could have achieved.  That is the essential connexion.  Of course, there are accessories.  A private detective coming urgently to see me with a notable tetradrachm in his pocket, which he announces to be the clue to a remarkable fraud—­well, really, Louis, one scarcely needs to be blind to see through that.”

“And Lord Seastoke?  I suppose you happened to discover that Nina Brun had gone there?”

“No, I cannot claim to have discovered that, or I should certainly have warned him at once when I found out—­only recently—­about the gang.  As a matter of fact, the last information I had of Lord Seastoke was a line in yesterday’s Morning Post to the effect that he was still at Cairo.  But many of these pieces—­” He brushed his finger almost lovingly across the vivid chariot race that embellished the reverse of the coin, and broke off to remark:  “You really ought to take up the subject, Louis.  You have no idea how useful it might prove to you some day.”