every way, and several incidents connected with it have opened up
to me a new vista of research, the possibilities of which are--er-
-very interesting and remarkable."

"Indeed!" murmured Courtney indifferently, his eyes fixed on the
slim, supple figure of the Princess Ziska as she slowly moved amid
her circle of admirers out of the ball-room, her golden skirts
gleaming sun-like against the polished floor, and the jewels about
her flashing in vivid points of light from the hem of her robe to
the snake in her hair.

"Yes," continued the Doctor, smiling and rubbing his hands, "I
think I have got the clue to a very interesting problem. But I see
you are absorbed--and no wonder! A charming woman, the Princess
Ziska--charming! Do you believe in ghosts?"

This question was put with such unexpected abruptness that
Courtney was quite taken aback.

"Ghosts?" he echoed. "No, I cannot say I do. I have never seen
one, and I have never heard of one that did not turn out a bogus."

"Oh! I don't mean the usual sort of ghost," said the Doctor,
drawing his shelving brows together in a meditative knot of criss-
cross lines over his small, speculative eyes. "The ghost that is
common to Scotch castles and English manor-houses, and that
appears in an orthodox night-gown, sighs, screams, rattles chains
and bangs doors ad libitum. No, no! That kind of ghost is composed
of indigestion, aided by rats and a gust of wind. No; when I say
ghosts, I mean ghosts--ghosts that do not need the midnight hour