...plucked too hard, or musical notes of a Certain quality break solid objects at a Distance."

I began to think I had got off Lightly. My face must have betrayed the Thought, for I saw his expression change. "Young man," he said, sternly reproving, "I could kill you in an instant, sitting here, without either of us moving a muscle."

I stared at him in amazement, unbelieving for a moment. But there was that in his tone and manner which carried conviction. I sat abashed, gravely disconcerted.

"Are you afraid of risks?" he said gently once more, but still with a note of reproof. "Understand this clearly. No man can acquire this kind of knowledge without risking death. God, misapplied, is the Devil. There is only one force in creation. Good and evil lie merely in its application."