"I did not send that wireless!"

"Then you actually came by the boat which arrived last night?—and to think that I was asleep in the same hotel! What an amazing—"

"Amazing indeed, Rob, and the result of a cunning and well planned scheme." He raised his eyes, looking fixedly at his son. "You understand the scheme; the scheme that could only have germinated in one mind—a scheme to cause me, your father, to—"

His voice failed and again his glance sought the weapon which lay so close to his feet. Partly in order to hide his emotion, he stooped, picked up the dagger, and threw it on the bed.

"For God's sake, sir," groaned Robert, "what were you doing here in my room with—that!"

Dr. Cairn stood straightly upright and replied in an even voice:

"I was here to do murder!"

"Murder!"

"I was under a spell—no need to name its weaver; I thought that a poisonous thing at last lay at my mercy, and by cunning means the primitive evil within me was called up, and braving the laws of God and man, I was about to slay that thing. Thank God!—"

He dropped upon his knees, silently bowed his head for a moment, and then stood up, self-possessed again, as his son had always known him. It had been a strange and awful awakening for Robert Cairn—to find his room illuminated by a lurid light, and to find his own father standing over him with a knife! But what had moved him even more deeply than the fear of these things, had been the sight of the emotion which had shaken that stern and unemotional man. Now, as he gathered together his scattered wits, he began to perceive that a malignant hand was moving above them, that his father, and himself, were pawns, which had been moved mysteriously to a dreadful end.