My legs gave way under me and I sank into my chair. As I did so my hand touched Mabel's, and I grasped hers tightly. It was cold as ice. Leaning toward me, she whispered in my ear:
"Don't make a scene! It is all quite true. You were run over an hour ago by a trolley car."
Not daring to believe my senses, I replied:
"And this house—?"
"Sh—h!" said Mabel. "It is only the ghost of a house,—the phantasmal reproduction of an old mansion that used to stand on this spot, where there has been an empty lot for fifteen years past."
"I—I think I understand," I gasped. Then, though my brain swam, I made a tremendous effort to summon up my courage and face composedly this dreadful situation. Addressing myself to the old woman opposite, I said:
"Perchance you were acquainted with the former occupants of this dwelling?"
"Oh, yes," she answered pleasantly. "I am somewhat distantly related to our host and hostess of this evening. They were drowned—lost on the ill-fated Ville de Paris. This house belonged to them, and not very long afterwards it was torn down."
"But suppose that the present owner of the lot were to build upon it?" I suggested. "It would be necessary to hold these charming entertainments elsewhere?"
"Not at all," she said, laughing and waving her fan. "The occupancy of the site by a real house would not interfere. It frequently happens, of course, that a building is put up on ground previously occupied by another dwelling. You must understand, though I might have supposed you knew it, that, while the material parts of a tenement may be removed at any time, its astral shell remains in perpetuity. Thus the ghosts of half a dozen or more dwellings may remain on the site occupied by a new and substantial structure. They are none the less real for being invisible to living eyes. The most remarkable instances of haunted houses that you have heard about are due to conditions of that sort,—several families of phantasms, perhaps, tenanting premises topographically coincident with a mansion which affords physical accommodation to people in the flesh. I trust I make myself clear?"