house, they halted for a moment while Platzoff unlocked a door, after
which they passed forward into a room, in the middle of which Ducie was
left standing while Platzoff relocked the door, and then busied himself
for a minute in trimming the lamp he had brought with him, which had
been his only guide through the dark and silent house, for the servants
had all gone to bed more than an hour ago.

Ducie, thus left to himself for a little while, had time for reflection.
The floor on which he was standing was covered with a thick, soft
carpet, consequently he was in one of the best rooms in the house. The
atmosphere of this room was penetrated with a very faint aroma of
pot-pourri, so faint that unless Captain Ducie's nose had been more than
ordinarily keen he would never have perceived it. To the best of his
knowledge there was only one room in Bon Repos that was permeated with
the peculiar scent of pot-pourri. That room was M. Platzoff's private
study, to which access was obtained through his bed-room. Ducie had been
only twice into this room, but he remembered two facts in connection
with it. First, the scent already spoken of; secondly, that besides the
door which opened into it from the bed-room, there was another door
which he had noticed as being shut and locked both times that he was
there. If the room in which they now were was really M. Platzoff's
study, they had probably obtained access to it through the second door.

While silently revolving these thoughts in his mind, Captain Ducie's
fingers were busy with the formation of two tiny paper pellets, each no
bigger than a pea. Unseen by Platzoff, he contrived to drop these
pellets on the carpet.

"I must really apologise," said the Russian, next moment, "for keeping
you waiting so long; but this lamp will not burn properly."