iately
anxious to find that creaking board which promised to narrow it further
yet.

Where should I seek it? In these rear halls, of course, but I hated to
be caught pacing them at this hour. Nixon's step had not roused it or
I should have noticed it, for I was, in a way, listening for this very
sound. It was not in the direct path then from the front door to the
kitchen. Was it on one side or in the space about the dining-room door
or where the transverse corridor met the main hall? All these floors
were covered in the old-fashioned way with carpet, which would seem to
show that no new boards had been laid and that the creaking one should
still be here.

I ventured to go as far as the transverse hall,--I was at full liberty
to enter the library. But no result followed this experiment; my
footsteps had never fallen more noiselessly. Where could the board be?
In aimless uncertainty I stepped into the corridor and instantly a creak
woke under my foot. I had located the direction in which one of the
so-called phantoms had fled. It was down this transverse hall.

Flushed with apparent success, I looked up at the walls on either side
of me. They were gray with paint and presented one unbroken surface from
base-board to ceiling, save where the two doorways opened, one into the
library, the other into the dining-room. Had the flying presence escaped
by either of these two rooms? I knew the dining-room well. I had had
several opportunities for studying its details. I thought I knew the
library; besides, Mr. Searles had been in the library when the shape
advanced upon him from the hall,--a fact eliminating that room as a
possible source of approach! What then was left? The recess which had
once served as an old-time entrance. Ah, that gave promise of something.
It projected directly toward where the adjacent walls had once held two
doors, between which any sort of mischief might take place. Say that the
Misses Quinlan had retained certain keys. What easier than for one of
them to enter the outer door, strike a light, open the inner one and
flash this light up through the house till steps or voices warned her of
an aroused family, when she had only to reclose the inside door, put out
the light and escape by the outer one.

But alas! at this point I remembered that this, as well as all other
outside doors, had invariably been protected by bolt, and that these
bolts had never been found disturbed. Veritably I was busying myself