leep,"
come from the impenetrable darkness. And when the lightning came again,
the white figure was gone.

I wandered around the courtyard, searching in vain for Sister Maddelena,
even until the moonlight broke through the torn and sweeping fringes of
the storm. I tried the door where the white figure vanished: it was
locked; but I had found what I sought, and, carefully noting its
location, went back to my room, but not to sleep.

In the morning the Cavaliere asked Rendel and me which of us had seen
the ghost, and I told him my story; then I asked him to grant me
permission to sift the thing to the bottom; and he courteously gave the
whole matter into my charge, promising that he would consent to
anything.

I could hardly wait to finish breakfast; but no sooner was this done
than, forgetting my morning pipe, I started with Rendel and the
Cavaliere to investigate.

"I am sure there is nothing in that cell," said Valguanera, when we came
in front of the door I had marked. "It is curious that you should have
chosen the door of the very cell that tradition assigns to Sister
Maddelena; but I have often examined that room myself, and I am sure
that there is no chance for anything to be concealed. In fact, I had the
floor taken up once, soon after I came here, knowing the room was that
of the mysterious Sister, and thinking that there, if anywhere, the
monastic crime would have taken place; still, we will go in, if you
like."

He unlocked the door, and we entered, one of us, at all events, with a
beating heart. The cell was very small, hardly eight feet square. There
certainly seemed no opportunity for concealing a body in the tiny
place; and although I sounded the floor and walls, all gave a solid,
heavy answer,--the unmistakable sound of masonry.

For the innocence of the floor the Cavaliere answered. He had, he said,
had it all removed, even to the curving surfaces of the vault below; yet
somewhere in this room the body of the murdered girl was concealed,--of
this I was certain. But where? There seemed no answer; and I was
compelled to give up the search for the moment, somewhat to the
amusement of Valguanera, who had watched curiously to see if I could
solve the mystery.

But I could not forget the subject, and toward noon started on another
tour of investigation. I procured the keys from the Cavaliere, and
examined the cells adjoining; they were apparently the same, each with
its window opposite the door, and n