asped Pender, catching his breath.

"Not exactly," the doctor said, with a grave smile, "but with your
assistance, perhaps. I shall want to test the conditions of the
house--to ascertain, impossible, the character of the forces, of this
strange personality that has been haunting you--"

"At present you have no idea exactly who--what--why--" asked the
other in a wild flurry of interest, dread and amazement.

"I have a very good idea, but no proof rather," returned the doctor.
"The effects of the drug in altering the scale of time and space, and
merging the senses have nothing primarily to do with the invasion. They
come to any one who is fool enough to take an experimental dose. It is
the other features of your case that are unusual. You see, you are now
in touch with certain violent emotions, desires, purposes, still active
in this house, that were produced in the past by some powerful and evil
personality that lived here. How long ago, or why they still persist so
forcibly, I cannot positively say. But I should judge that they are
merely forces acting automatically with the momentum of their terrific
original impetus."

"Not directed by a living being, a conscious will, you mean?"

"Possibly not--but none the less dangerous on that account, and more
difficult to deal with. I cannot explain to you in a few minutes the
nature of such things, for you have not made the studies that would
enable you to follow me; but I have reason to believe that on the
dissolution at death of a human being, its forces may still persist and
continue to act in a blind, unconscious fashion. As a rule they speedily
dissipate themselves, but in the case of a very powerful personality
they may last a long time. And, in some cases--of which I incline to
think this is one--these forces may coalesce with certain non-human
entities who thus continue their life indefinitely and increase their
strength to an unbelievable degree. If the original personality was
evil, the beings attracted to the left-over forces will also be evil. In
this case, I think there has been an unusual and dreadful aggrandisement
of the thoughts and purposes left behind long ago by a woman of
consummate wickedness and great personal power of character and
intellect. Now, do you begin to see what I am driving at a little?"

Pender stared fixedly at his companion, plain horror showing in his
eyes. But he found nothing to say, and the doctor continued--

"In your case, pred