am unable to name, although my memory of it is as vivid to-day as was
my sense of it then. The situation was embarrassing; I rose to take
my leave. At this he seemed to recover himself.

"Please be seated," he said; "it is nothing--no one is there."

But the tapping was repeated, and with the same gentle, slow
insistence as before.

"Pardon me," I said, "it is late. May I call to-morrow?"

He smiled--a little mechanically, I thought. "It is very delicate of
you," said he, "but quite needless. Really, this is the only room in
the tower, and no one is there. At least--" He left the sentence
incomplete, rose, and threw up a window, the only opening in the wall
from which the sound seemed to come. "See."

Not clearly knowing what else to do I followed him to the window and
looked out. A street-lamp some little distance away gave enough
light through the murk of the rain that was again falling in torrents
to make it entirely plain that "no one was there." In truth there
was nothing but the sheer blank wall of the tower.

Dampier closed the window and signing me to my seat resumed his own.

The incident was not in itself particularly mysterious; any one of a
dozen explanations was possible (though none has occurred to me), yet
it impressed me strangely, the more, perhaps, from my friend's effort
to reassure me, which seemed to dignify it with a certain
significance and importance. He had proved that no one was there,