in my pocket.

[Illustration: "GOOD HEAVENS! WHAT HAD HAPPENED?"]

It was troublesome to unlock, because the key was a little rusty, and it
was more than evident that the heavy doors had not been opened for some
time. Both these doors were made of glass. When shut, they resembled in
shape and appearance an ordinary old-fashioned window. The glass was set
in deep mullions. It was thick, was of a peculiar shade of light blue,
and was evidently of great antiquity. I opened the doors and went
inside. The wardrobe was so roomy that I could stand upright with
perfect comfort. It was empty, and was lined through and through with
solid oak. I struck a light and began to examine the interior with care.
After a great deal of patient investigation I came across a notch in the
wood. I pressed my finger on this, and immediately a little panel slid
back, which revealed underneath a small button. I turned the button and
a door at the back of the wardrobe flew open. A flood of sunlight poured
in, and stepping out, I found myself in another room. I looked around me
in astonishment. This was a lady's chamber. Good heavens! what had
happened? I was in Lady Studley's room. Shutting the mysterious door of
the wardrobe very carefully, I found that all trace of its existence
immediately vanished.

There was no furniture against this part of the wall. It looked
absolutely bare and smooth. No picture ornamented it. The light paper
which covered it gave the appearance of a perfectly unbroken pattern. Of
course, there must be a concealed spring somewhere, and I lost no time
in feeling for it. I pressed my hand and the tips of my fingers in every
direction along the wall. Try as I would, however, I could not find the
spring, and I had at last to leave Lady Studley's room and go back to
the one occupied by her husband, by the ordinary door.

Once more I re-entered the wardrobe and deliberately broke off the
button which opened the secret door from within. Anyone who now entered
the wardrobe by this door, and shut it behind him, would find it
impossible to retreat. The apparition, if it had material foundation,
would thus find itself trapped in its own net.

What could this thing portend?

I had already convinced myself that if Sir Henry were the subject of a
hallucination, I also shared it. As this was impossible, I felt certain
that the apparition had a material foundation. Who was the person who
glided night after night into Lady Studley's