sive replies an intention to mislead me into a
belief that he was actuated towards me by friendly motives. Therefore
my antagonism increased. He had defied me, and I would give him into
custody.

Presently there came a loud knocking at the door, and, upon my opening
it, a police-sergeant stood upon the threshold.

"I give this man into custody," I said, addressing him and pointing to
the Frenchman.

"Upon what charge, sir?" asked the burly officer, whose broad
shoulders filled the doorway, while I saw a constable standing behind
him.

"On suspicion of being associated with the theft of the diamonds of
the Archduchess Marie Louise," I replied.

"Come, monsieur," laughed my visitor, speaking again in English, "I
think we have carried this sufficiently far." And, placing his hand in
his breast-pocket, he produced a small folded yellow card bearing his
photograph, which he handed to me. "Read that!" he added, with a laugh
of triumph.

I saw that the printed card was headed "Prefecture de Police, Ville de
Paris," and that it was signed, countersigned, and bore a large red
official seal.

Quickly I scanned it, and, to my abject dismay, realized that Henri
Guertin was chief of the first section of the _surete_--he was one of
the greatest detectives of France!

I stammered something, and then, turning to the sergeant, red and
ashamed, I admitted that I had made a mistake in attempting to arrest
so distinguished an official.

The two metropolitan officers held the card in their hands, and,
unable to read French, asked me to translate it for them, which I did.

"Why," cried the sergeant, "Monsieur Guertin is well known! His name
figures in the papers only this morning as arresting two Englishmen in
Paris for a mysterious murder alleged to have been committed in some
house in Bayswater!"

"In Bayswater!" I gasped. "In Porchester Terrace?"

"Yes," replied the famous French detective. "It is true that I know
Reckitt and Forbes. But I only knew them in order to get at the truth.
They never suspected me, and early yesterday morning I went to the
snug little apartments they have in the Rue de Rouen, and arrested
them, together with two young Frenchmen named Terassier and Brault.
Concealed beneath a loose board in the bedroom of the last-named man I
found the missing gems."

"Then Terassier and Brault were the two men who met the others in
Stamford, and carried the diamonds across to the Continent, intending
to dispos