I made up my mind at once that if I were to escape
at all, it must be through her chamber.

It was about this time that the truth as to the manner in which I was
attached to the wall flashed upon me. I could see it all now, and
wondered how I had not understood it before. I have already explained
that the rings to which my ankles were attached ended in round rods or
bolts that passed through the wall. But the bolts turned easily with
every movement of my body, instead of being (as one would have
expected) firmed into the thickness of the wall. Now it was all clear
as an invoice. The bolts passed right through into the chamber
occupied by Elsie, and were there attached either to other similar
rings or held in place by a crossbar of some sort.

I used the code--my foolish thought for Joe, now so useful--to ask the
girl if she could see anything at the place upon which I knocked with
my feet. She replied that it was impossible, because in that place
there was a deep cupboard of which she had not got the key. Now, I
know the locks of cupboard doors. I sell them. And the fact is that
most of them are worthless as fastenings, except perhaps a few like the
one in Miss Elsie's room, which had been planned by the monks some
hundred years ago.

But even so, the lock would almost certainly have had to be
renewed--probably quite recently--in view of the use to which the
underground passages and cellars were to be put. I therefore "knocked"
a message through to Elsie to secrete a stout knife. She had it
already. I might have expected as much of her. Then I told her how to
slide the blade of the knife with its back downward into the crack of
the door. The supple bend of the knife blade, taking the shape of the
bolt, would in all probability after a little trial cause it to slide
back easily.

After a little Elsie succeeded. The bolt, as I expected, was a biased
one, not square on the face, and hardly caught into the bolt hole at
all. It had come from my own shop, and I knew its capabilities. They
make them by the hundred gross, all as like as peas, and just
sufficiently strong to keep out the cat. But mostly, if people think a
place is locked, it _is_ locked--especially women.

I could hardly wait the reply, after Elsie had been into the deep
cupboard. It was all I could hope for. The bolts came through into
the cupboard about three feet from the floor, which showed that my
chamber was higher than hers; th