the personals.' They are often the keys
to intrigues, that are not always brass-headed, but which are none the
less interesting. This advertisement interested me specially; the woman
of the key surrounded it with a kind of mystery. Evidently she valued
the key, since she promised a big reward for its restoration! And I
thought on these six letters: M. A. T. H. S. N. The first four at once
pointed to a Christian name; evidently I said Math is Mathilde. But I
could make nothing of the two last letters. So I threw the journal
aside and occupied myself with other matters. Four days later, when the
evening paper appeared with enormous head-lines announcing the murder of
Mademoiselle Stangerson, the letters in the advertisement mechanically
recurred to me. I had forgotten the two last letters, S. N. When I saw
them again I could not help exclaiming, 'Stangerson!' I jumped into
a cab and rushed into the bureau No. 40, asking: 'Have you a letter
addressed to M. A. T. H. S. N.?' The clerk replied that he had not. I
insisted, begged and entreated him to search. He wanted to know if I
were playing a joke on him, and then told me that he had had a letter
with the initials M. A. T. H. S. N, but he had given it up three days
ago, to a lady who came for it. 'You come to-day to claim the letter,
and the day before yesterday another gentleman claimed it! I've had
enough of this,' he concluded angrily. I tried to question him as to the
two persons who had already claimed the letter; but whether he wished to
entrench himself behind professional secrecy,--he may have thought that
he had already said too much,--or whether he was disgusted at the joke
that had been played on him--he would not answer any of my questions."

Rouletabille paused. We all remained silent. Each drew his own
conclusions from the strange story of the poste restante letter. It
seemed, indeed, that we now had a thread by means of which we should be
able to follow up this extraordinary mystery.

"Then it is almost certain," said Monsieur Stangerson, "that my daughter
did lose the key, and that she did not tell me of it, wishing to spare
any anxiety, and that she begged whoever had found it to write to
the poste restante. She evidently feared that, by giving our address,
inquiries would have resulted that would have apprised me of the loss of
the key. It was quite logical, quite natural for her to have taken that
course--for I have been robbed once before."

"Where was