“I will not kill you,” said the Duke, leaning a little nearer and the awful light in his eyes growing intenser—­for awful it was and made his pale face deadly.  “How I can force you to it I have shown you—­and brought you here to prove.  For that, I meant that we should fight alone.  Myself, I knew, I could hold from killing you, howsoever my blood might tempt me.  You, I knew, I could keep from killing me, which I knew you would have done if you could, by foul means if not fair.  I would not have it said I was forced to fight to shield that lady’s name—­so I would have no witness if it could be helped.  And you will keep the encounter secret, for I command you.”

Sir John started up, leaning upon his elbow, catching his breath, and his wicked face a white flame.

“Curse you!” he shrieked again, blaspheming at a thing he had not dreamed of, and which came upon him like a thunderbolt.  “Curse your soul—­you love her!”

The deadly light danced—­he saw it—­in his Grace’s eyes, but his countenance was a marble mask with no human quiver of flesh in any muscle of it.

“I command you,” he went on; “having proved I can enforce.  I have the blood of savage devils in me, come down to me through many hundred years.  All my life I have kept them at bay.  Until late I did not know how savage they were and what they could make me feel.  I could do to you, as you lie there, things a man who is of this century, and sane, cannot do.  You know I can strike where I will.  If you slight that lady’s name again I will not kill”—­he raised himself from his sword and stood his full height, the earliest gold of the sun shining about him—­“I will not kill you, but—­so help me God!—­I will fight with you once more, and I will leave you so maimed and so disfigured that you can woo no woman to ruin again and jest at her shame and agony with no man—­for none can bear to look at you without a shudder—­and you will lie and writhe to be given the coup de grace.”  He lifted the hilt of his sword and kissed it.  “That I swear,” he said, “by this first dawning of God’s sun.”

When later my lord Duke returned to the town and got his horse and rode across the moors the shortest road to Camylott, he felt suddenly that his body was slightly trembling.  He looked down at his hands and saw they were unsteady, and a strange look—­as of a man slowly awakening from a dream—–­ came over his face.  ’Twas this he felt—­as if the last two hours he had lived in a dream or had been another man than himself, perhaps some bloody de Mertoun, who had for ages been dry, light dust.  The devils which had been awake in him had been devils so awful as he well knew—­not devils to possess and tear a man in the days of good Queen Anne, but such as, in times long past, possessed those who slew, and hacked, and tortured, and felt an enemy a prey to be put to peine forte et dure.  He drew his glove across his brow and found it damp.  This dream had taken hold upon him three hours before,