“Denzil, have you ever read Shakespeare?”

Denzil started and forced a smile.

“Why, yes, of course!”

“Then you know the lines—­

’There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy?’

The Princess Ziska was one of those ‘things.’”

Denzil regarded him in wonderment.

“What do you mean?”

“Oh, of course, you will think me insane,” said the Doctor, resignedly.  “People always take refuge in thinking that those who tell them uncomfortable truths are lunatics.  You’ve heard me talk of ghosts?—­ghosts that walk and move about us like human beings?- -and they are generally very brilliant and clever impersonations of humanity, too—­and that nevertheless are not human?”

Denzil assented.

“The Princess Ziska was a ghost!” concluded the Doctor, folding his arms very tightly across his chest and nodding defiantly.

“Nonsense!” cried Denzil.  “You are mad!”

“Precisely the remark I thought you would make!” and Dr. Dean unfolded his arms again and smiled triumphantly.  “Therefore, my dear boy, let us for the future avoid this subject.  I know what I know; I can distinguish phantoms from reality, and I am not deceived by appearances.  But the world prefers ignorance to knowledge, and even so let it be.  Next time I meet a ghost I’ll keep my own counsel!” He paused a moment,—­then added:  “You remember I told you I was hunting down that warrior of old time, Araxes?”

Denzil nodded, a trifle impatiently.

“Well,” resumed the Doctor slowly,—­“Before we left Egypt I found him!  But how I found him, and where, is my secret!”

Society still speaks occasionally of Armand Gervase, and wonders in its feeble way when he will be “tired” of the Egyptian beauty he ran away with, or she of him.  Society never thinks very far or cares very much for anything long, but it does certainly expect to see the once famous French artist “turn up” suddenly, either in his old quarters in Paris, or in one or the other of the fashionable resorts of the Riviera.  That he should be dead has never occurred to anyone, except perhaps Dr. Maxwell Dean.  But Dr. Dean has grown extremely reticent—­almost surly; and never answers any questions concerning his Scientific Theory of Ghosts, a work which, when published, created a great deal of excitement, owing to its singularity and novelty of treatment.  There was the usual “hee-hawing” from the donkeys in the literary pasture, who fondly imagined their brayings deserved to be considered in the light of serious opinion;—­and then after a while the book fell into the hands of scientists only,—­men who are beginning to understand the discretion of silence, and to hold their tongues as closely as the Egyptian priests of old did, aware that the great majority of men are never ripe for knowledge.  Quite lately Dr. Dean attended two weddings,—­one being