It was approaching the evening of the third day after riding forth upon his mission when Sholto, sleepless yet quite unconscious of weariness, approached the loch of Carlinwark and the cottage of Brawny Kim. West and south he had raised the Douglas country as it had never been raised before. And now behind him every armiger and squire, every spearman and light-foot archer, was hasting Edinburgh-ward, eager to be first to succour the young and headstrong chief of his great house.

Sholto had ridden and cried the slogan as was his duty, without allowing his mind to dwell over much upon whether all might not arrive too late. And ever as he rode out of village or across the desolate moors from castle to fortified farmhouse, it seemed that not he but some other was upon this quest.

Something sterner and harder stirred in his breast. Light-hearted Sholto MacKim, the careless lad of the jousting day, the proud young captain of the Earl's guard, was dead with all his vanity. And in his place a man rode southward grim and determined, with vengeful angers a-smoulder in his bosom,—hunger, thirst, love, the joy of living and the fear of death all being swallowed up by deadly hatred of those who had betrayed his master.

Maud Lindesay was doubtless within a few miles of Sholto, yet he scarcely gave even his sweetheart a thought as he urged his weary grey over the purple Parton moors towards the loch of Carlinwark and the little hamlet nestling along its western side under the ancient thorn trees of the Carlin's hill.

He rode down over the green and empty Crossmichael braes on which the broom pods were crackling in the afternoon sunshine, through hollows where the corn lingered as though unwilling to have done with such a scene of beauty, and find itself mewed in dusty barns, ground in mills, or close pressed in thatched rick. He breasted the long smooth rise and entered the woods which encircle the bright lakelet of Carlinwark, the pearl of all southland Scottish lochs.

With a strange sense of detachment he looked down upon the green sward between him and his mother's gable end, upon which as a child he had wandered from dawn to dusk. Then it was nearly as large as the world, and the grass was most comfortable to bare feet. There were children playing upon it now, even as there had been of old, among them his own little sister Magdalen, whose hair was spun gold, and her eyes blue as the forget-me-not on the marshes of the Isle Wood. The children were dressed in white, five little girls in all, as for a festal day, and their voices came upward to Sholto's ear through the arches of the great beeches which studded the turf with pavilions of green shade, tenderly as they had done to that of William Douglas in the spring-time of the year.

The minor note, the dying fall of the innocent voices, tugged at his heartstrings. He could hear little Magdalen leading the chorus:

It was at "Fair Maid" they were playing, the mystic dance of Southland maidenhood, at whose vestal rites no male of any age was ever permitted to be present. The words broke in upon the gloom which oppressed Sholto's heart. Momentarily he forgot his master and saw Maud Lindesay with the little Margaret Douglas of whom the children sang, once again gathering the gowans on the brae sides of Thrieve or perilously reaching out for purple irises athwart the ditches of the Isle.

As Sholto MacKim listened to the quaint and moving lullaby, suddenly there came into the field of his vision that which stiffened him into a statue of breathing marble.

For without clatter of accoutrement or tramp of hoof, without companion or attendant, a white palfrey had appeared through the green arches of the woodlands. A girl was seated upon the saddle, swaying with gentle movement to the motion of her steed. At the sight of her figure as she came nearer a low cry of horror and amazement broke from Sholto's lips.

It was the Lady Sybilla.

Yet he knew that he had left her behind him in Edinburgh, the siren temptress of Earl Douglas, the woman who had led his master into the power of the enemy, she for whose sake he had refused the certainty of freedom and life. Anger against this smiling enchantress suddenly surged up in Sholto's heart.

"Halt there—on your life!" he cried, and urged his wearied steed forward. Like dry leaves before a winter wind, the children were dispersed every way by the gust of his angry shout. But the maiden on the palfrey either heeded not or did not hear.

Whereupon Sholto rode furiously crosswise to intercept her. He would learn what had befallen his master. At least he would avenge him upon one—the chiefest and subtlest of his enemies. But not till he had come within ten paces did the Lady Sybilla turn upon him the fulness of her regard. Then he saw her face. It broke upon him sudden as the sight of imminent hell to one sure of salvation. He had expected to find there gratified ambition, sated lust, exultant pride, cruelest vengeance. He saw instead as it had been the face of an angel cast out of heaven, or perhaps, rather, of a martyr who has passed through the torture chamber on her way to the place of burning.

The sight stopped Sholto stricken and wavering. His anger fell from him like a cloak shed when the sun shines in his strength.

The Lady Sybilla's face showed of no earthly paleness. Marble white it was, the eyes heavy with weeping, purple rings beneath accentuating the horror that dwelt eternally in them. The lips that had been as the bow of Apollo were parted as though they had been singing the dirge of one beloved, and ever as she rode the tears ran down her cheeks and fell on her white robe, and lower upon her palfrey's mane.

She looked at Sholto when he came near, but not as one who sees or recognises. Rather, as it were, dumb, drunken, besotted with grief, looked forth the soul of the Lady Sybilla upon the captain of the Douglas guard. She heeded not his angry shout, for another voice rang in her ears, speaking the knightliest words ever uttered by a man about to die. Sholto's sword was raised threateningly in his hand, but Sybilla saw another blade gleam bright in the morning sun ere it fell to rise again dimmed and red. Therefore she checked not her steed, nor turned aside, till Sholto laid his fingers upon her bridle-rein and leaped quickly to the ground, sword in hand, leaving his own beast to wander where it would.

"What do you here?" he cried. "Where is my master? What have they done to him? I bid you tell me on your life!"

Sholto's voice had no chivalrous courtesy in it now. The time for that had gone by. He lowered his sword point and there was tense iron in the muscles of his arm. He was ready to kill the temptress as he would a beautiful viper.

The Lady Sybilla looked upon him, but in a dazed fashion, like one who rests between the turns of the rack. In a little while she appeared to recognise him. She noted the sword in his hand, the death in his eye—and for the first time since the scene in the courtyard of Edinburgh Castle, she smiled.

Then the fury in Sholto's heart broke suddenly forth.

"Woman," he cried, "show me cause why I should not slay you. For, by God, I will, if aught of harm hath overtaken my master. Speak, I bid you, speak quickly, if you have any wish to live."

But the Lady Sybilla continued to smile—the same dreadful, mocking smile—and somehow Sholto, with his weapon bare and his arm nerved to the thrust, felt himself grow weak and helpless under the stillness and utter pitifulness of her look.

"You would kill me—kill me, you say—" the words came low and thrilling forth from lips which were as those of the dead whose chin has not yet been bound about with a napkin, "ah, would that you could! But you cannot. Steel will not slay, poison will not destroy, nor water drown Sybilla de Thouars till her work be done!"

Sholto escaped from the power of her eye.

"My master—" he gasped, "my master—is he well? I pray you tell me."

Was it a laugh he heard in answer? Rather a sound, not of human mirth but as of a condemned spirit laughing deep underground. Then again the low even voice replied out of the expressionless face.

"Aye, your master is well."

"Ah, thank God," burst forth Sholto, "he is alive."

The Lady Sybilla moved her hand this way and that with the gesture of a blind man groping.

"Hush," she said, "I only said that he was well. And he is well. As I am already in the place of torment, I know that there is a heaven for those who die as William Douglas died."

Sholto's cry rang sudden, loud, despairing.

"Dead—dead—Earl William dead—my master dead!"

He dropped the palfrey's rein, which till now he had held. His sword fell unheeded on the turf, and he flung himself down in an agony of boyish grief. But from her white palfrey, sitting still where she was, the maiden watched the paroxysms of his sorrow. She was dry eyed now, and her face was like a mask cut in snow.

Then as suddenly recalling himself, Sholto leaped from the ground, snatched up his sword, and again passionately advanced upon the Lady Sybilla.

"You it was who betrayed him," he cried, pointing the blade at her breast; "answer if it were not so!"

"It is true I betrayed him," she answered calmly.

"You whom he loved—God knows how unworthily—"

"God knows," she said simply and calmly.

"You betrayed him to his death. Why then should not I kill you?"

Again she smiled upon him that disarming, hopeless, dreadful smile.

"Because you cannot kill me. Because it were too crowning a mercy to kill me. Because, for three inches of that blade in my heart, I would bless you through the eternities. Because I must do the work that remains—"

"And that work is—?"

"Vengeance!!"

Sholto was silent, trying to piece things together. He found it hard to think. He was but a boy, and experience so strange as that of the Lady Sybilla was outside him. Yet vaguely he felt that her emotion was real, more real perhaps than his own instinct of crude slaying—the desire of the wasp whose nest has been harried to sting the first comer. This woman's hatred was something deadlier, surer, more persistent.

"Vengeance—" he said at last, scarce knowing what he said, "why should you, who betrayed him, speak of avenging him?"

"Because," said the Lady Sybilla, "I loved him as I never thought to love man born of woman. Because when the fiends of the pit tie me limb to limb, lip to lip, with Judas who sold his master with a kiss, when they burn me in the seventh hell, I shall remember and rejoice that to the last he loved me, believed in me, gloried in his love for me. And God who has been cruel to me in all else, will yet do this thing for me. He will not let William Douglas know that I deceived him or that he trusted me in vain."

"But the Vengeance that you spoke of—what of that?" said Sholto, dwelling upon that which was uppermost in his own thought.

"Aye," said the Lady Sybilla, "that alone can be compassed by me. For I am bound by a chain, the snapping of which is my death. To him who, in a far land, devised all these things, to the man who plotted the fall of the Douglas house—to Gilles de Retz, Marshal of France, I am bound. But—I shall not die—even you cannot kill me, till I have brought that head that is so high to the hempen cord, and delivered the foul fiend's body to the fires of both earth and hell."

"And the Chancellor Crichton—the tutor Livingston—what of them?" urged Sholto, like a Scot thinking of his native traitors.

The Lady Sybilla waved a contemptuous hand.

"These are but lesser rascals—they had been nothing without their master and mine. You of the Douglas house must settle with them."

"And why have you returned to this country of Galloway?" said Sholto. "And why are you thus alone?"

"I am here," said the Lady Sybilla, "because none can harm me with my work undone. I travel alone because it suits my mood to be alone, because my master bade me join him at your town of Kirkcudbright, whence, this very night, he takes ship for his own country of Brittany."

"And why do you, if as you say you hate him so, continue to follow him?"

"Ah, you are simple," she said; "I follow him because it is my fate, and who can escape his doom? Also, because, as I have said, my work is not yet done."

She relapsed into her former listless, forth-looking, unconscious regard, gazing through him as if the young man had no existence. He dropped the rein and the point of his sword with one movement. The white palfrey started forward with the reins loose on its neck. And as she went the eyes of the Lady Sybilla were fixed on the distant hills which hid the sea.

So, leaving Sholto standing by the lakeside with bowed head and abased sword, the strange woman went her way to work out her appointed task.

But ere the Lady Sybilla disappeared among the trees, she turned and spoke once more.

"I have but one counsel, Sir Knight. Think no more of your master. Let the dead bury their dead. Ride to Thrieve and never once lose sight of her whom you call your sweetheart, nor yet of her charge, Margaret Douglas, the Maid of Galloway, till the snow falls and winter comes upon the land."