Astounding Stories of Super-Science, August 1930

Ribiera snarled. "Tio mio," he protested angrily, "you promised me--" "Your will in many things," said The Master gently, "but not in all. Remember that you have much to learn, hijo mio. I have taught you to prepare my little medicine, it is true. That is so you can take my place if age infirmity shall carry me away." The Master folded his hands with an air of pious resignation. "But you must learn policy. The Senorita Canalejas belongs to the Senor Bell." Jamison was staring, now, but Bell's eyes had narrowed to mere slits. "You see," said The Master gently, to him, "I desire your friendship. You may go where you will. You may take the Senorita Canalejas with you. You will have enough of the antidote to my little medicine to keep you sane for perhaps a week. In one week you may go far, with her. You may do many things. But you cannot find a place of safety for her. I still have a little power, Senor. If you take her with you, your hands will writhe again. Your body will become uncontrollable. Your eyes, staring and horror-struck, will observe your own hands rending her. While your brain is yet sane you will see this body of yours which now desires her so ardently, tearing at and crushing that delicate figure, gouging out her eyes, battering her tender flesh, destroying her.... Have you ever seen what a man who has taken my little medicine does to a human being at his mercy?"