h the thief had torn
the jewels from Sonia Danidoff's neck. He next considered the two
windows which, with the door opening on to the gallery, were the only
means of entrance and exit the room had. There were strong iron shutters
behind the windows: these could not be very easily opened: in any case,
it was impossible to close them again from the outside. The thief must
have been in the house, probably in the ball-room, and had followed the
Princess into this little retiring-room.... But what had been the
Princess's motive for coming here alone? Monsieur Havard had learned
that the room had not been thrown open to the other guests. Then he
perceived that the lace at the bottom of her dress was undone. He bent
down and examined it carefully: two pins, hastily stuck in, kept
together a piece of this lace.... The conclusion Monsieur Havard came to
was, that the Princess having a rent in her dress had wished to be alone
for a minute or two in order to repair the damage, and that while she
was stooping towards the bottom of her skirt the assassin had thrown her
to the ground and despoiled her of her jewels.

The chief of the detective force turned to Thomery abruptly:

"I shall be obliged to follow a course of action which may rather annoy
your guests; but they must excuse me. Everything leads me to think that
the guilty person is on the premises, since no one has gone away.... I
must hold an investigation at once. I am going to cross-examine your
guests--probe them thoroughly--and I wish to put them through their
paces in your office, Monsieur Thomery, one by one.... I will begin ...
with you ... so that your guests take my questioning with a good grace
... it is only a mere matter of form--a pure formality!..."

* * * * *

The investigations were lengthy and trying and led to no result
whatever.

* * * * *

Fandor, who was preoccupied by this fresh drama in which he had taken
some part--far too slight to please him--was putting on his overcoat
when he stopped dead.

A voice--an unrecognisable voice--had murmured in his ear:

"Attention! Fandor!... It is serious!..."

Our journalist turned round in a flash. Ah, this time he would find out
who the mysterious unknown was--the unknown, who wished to influence by
word written and word spoken, the course of these investigations he had
taken in hand:

Anonymous friend?

Concealed adversary?

He must, at