e 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."

"I really think I must," replied Carlyle grimly. "Two hundred and
fifty pounds the original of this cost, I believe."

"Cheap, too; it would make five hundred pounds in New York to-day. As
I was saying, many are literally unique. This gem by Kimon is--here is
his signature, you see; Peter is particularly good at lettering--and
as I handled the genuine tetradrachm about two years ago, when Lord
Seastoke exhibited it at a meeting of our society in Albemarle Street,
there is nothing at all wonderful in my being able to fix the locale
of your mystery. Indeed, I feel that I ought to apologize for it all
being so simple."

"I think," remarked Mr. Carlyle, critically examining the loose
threads on his left boot, "that the apology on that head would be more
appropriate from me."

THE KNIGHT'S CROSS SIGNAL PROBLEM

"Louis," exclaimed Mr. Carrados, with the air of genial gaiety that
Carlyle had found so incongruous to his conception of a blind man,
"you have a mystery somewhere about you! I know it by your step."

Nearly a month had passed since the incident of the false Dionysius
had led to the two men meeting. It was now December. Whatever Mr.
Carlyle's step might indicate to the inner eye it betokened to the
casual observer the manner of a crisp, alert,