But there was something much stranger still. Admitting that they had
been able to force the doors of his flat--and this he was compelled to
admit, though there was no mark to show it--how had they succeeded in
entering the bedroom? He turned the key and pushed the bolt as he did
every evening, in accordance with a habit from which he never departed.
And, nevertheless--the fact was undeniable--the crystal stopper had
disappeared without the lock or the bolt having been touched. And,
although Lupin flattered himself that he had sharp ears, even when
asleep, not a sound had waked him!

He took no great pains to probe the mystery. He knew those problems too
well to hope that this one could be solved other than in the course of
events. But, feeling very much put out and exceedingly uneasy, he then
and there locked up his entresol flat in the Rue Matignon and swore that
he would never set foot in it again.

And he applied himself forthwith to the question of corresponding with
Vaucheray or Gilbert.

Here a fresh disappointment awaited him. It was so clearly understood,
both at the Sante Prison and at the Law Courts, that all communication
between Lupin and the prisoners must be absolutely prevented, that a
multitude of minute precautions were ordered by the prefect of police
and minutely observed by the lowest subordinates. Tried policemen,
always the same men, watched Gilbert and Vaucheray, day and night, and
never let them out of their sight.

Lupin, at this time, had not yet promoted himself to the crowning honour
of his career, the post of chief of the detective-service,* and,
consequently, was not able to take steps at the Law Courts to insure the