"In the attic corridor the trail became faint, the prints almost ceasing as they merged with the dark carpet. I could still, however, discern the strange single path of the entity which had gone first, and this led straight to the closed door of Marsh's studio, disappearing beneath it at a point about halfway from side to side. Evidently it had crossed the threshold at a time when the door was wide open. * * * * * "Sick at heart, I tried the knob and found the door unlocked. Opening it, I paused in the waning north light to see what fresh nightmare might be waiting me. There was certainly something human on the floor, and I reached for the switch to turn on the chandelier. "But as the light flashed up, my gaze left the floor and its horror--that was Marsh, poor devil!--to fix itself frantically and incredulously upon the living thing that cowered and stared in the open doorway leading to Marsh's bedroom. It was a tousled, wild-eyed thing, crusted with the dried blood and carrying in its hand a wicked machete which had been one of the ornaments of the studio wall. Yet even in that awful moment I recognized it as one whom I had thought more than a thousand miles away. It was my own boy Denis--or the maddened wreck which had once been Denis. "The sight of me seemed to bring back a trifle of sanity--or at least of memory--in the poor boy. He straightened up and began to toss his head about as if trying to shake free from some enveloping influence. I could not speak a word, but moved my lips in an effort to get back my voice. My eyes wandered for a moment to the figure on the floor in front of the heavily draped easel--the figure toward which the strange blood-trail led, and which seemed to be tangled in the coils of some dark, ropy object. The shifting of my glance apparently produced some impression in the twisted brain of the boy, for suddenly he began to mutter in a hoarse whisper, the purport of which I was soon able to catch. "'I had to exterminate her--she was the devil!--the summit of high-priestess of all evil--the spawn of the pit--Marsh knew, and tried to warn me. Good old Frank! I didn't kill him, though I was ready to before I realized. But I went down there and killed her--then that cursed hair----' "I listened in horror as Denis choked, paused, and began again.