“And the nature of this⁠—er⁠—invasion?” stammered the bewildered writer of humorous tales.

“There is no reason why I should not say at once that I do not yet quite know,” replied Dr. Silence. “I may first have to make one or two experiments⁠—”

“On me?” gasped 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.