mystery which to-night baffles the police of London."

At these unexpected words, which carried in them something of the
tone of a challenge, the gentlemen about the table started as
suddenly as though the American had fired a pistol in the air, and
Sir Andrew halted, abruptly, and stood observing him with grave
surprise.

The gentleman with the black pearl was the first to recover.

"Yes, yes," he said, eagerly, throwing himself across the table. "A
mystery that baffles the police of London. I have heard nothing of
it. Tell us at once, pray do--tell us at once."

The American flushed uncomfortably, and picked, uneasily, at the
table-cloth.

"No one but the police has heard of it," he murmured, "and they only
through me. It is a remarkable crime, to which, unfortunately, I am
the only person who can bear witness. Because I am the only witness,
I am, in spite of my immunity as a diplomat, detained in London by
the authorities of Scotland Yard. My name," he said, inclining his
head, politely, "is Sears, Lieutenant Ripley Sears, of the United
States Navy, at present Naval Attache to the Court of Russia. Had I
not been detained to-day by the police, I would have started this
morning for Petersburg."

The gentleman with the black pearl interrupted with so pronounced an
exclamation of excitement and delight that the American stammered and
ceased speaking.