, stifling, breathless atmosphere, which dimmed the
eyes and baffled the most clear-sighted.

The magistrate in charge of the case fell ill. Four days later, his
successor confessed that the matter was beyond him.

Two tramps were arrested and at once released. Another was pursued, but
not caught; moreover, there was no evidence of any sort or kind against
him. In short, it was nothing but one helpless muddle of mist and
contradiction.

An accident, the merest accident led to the solution, or rather produced
a series of circumstances that ended by leading to the solution. A
reporter on the staff of an important Paris paper, who had been sent to
make investigations on the spot, concluded his article with the
following words:

"I repeat, therefore, that we must wait for fresh events, fresh facts;
we must wait for some lucky accident. As things stand, we are simply
wasting our time. The elements of truth are not even sufficient to
suggest a plausible theory. We are in the midst of the most absolute,
painful, impenetrable darkness. There is nothing to be done. All the
Sherlock Holmeses in the world would not know what to make of the
mystery, and Arsene Lupin himself, if he will allow me to say so, would
have to pay forfeit here."

* * * * *

On the day after the appearance of that article, the newspaper in
question printed this telegram:

"Have sometimes paid forfeit, but never over such a silly thing as
this. The Saint-Nicolas tragedy is a mystery for babies.

"ARSENE LUPIN."

And the editor added:

"We insert this telegram as a matter of curiosity, for it is
obviously the work of a wag. Arsene Lupin, past-master though he be
in the art of practical joking, would be the last man to display
such childish flippancy."

Two days elapsed; and then the paper published the famous letter, so
precise and categorical in its conclusions, in which Arsene Lupin
furnished the solution of the problem. I quote it in full:

"Sir:

"You have taken me on my weak side by defying me. You challenge me,
and I accept the challenge. And I will begin by declaring once more
that the Saint-Nicolas tragedy is a mystery for babies. I know
nothing so simple, so natural; and the proof of the simplicity
shall lie in the succinctness of my demonstration. It is contained
in these few words: when