Perceval leapt from his couch, and with naught upon him but his vest and doublet, he went with his sword in hand to the gate, and there he saw two poor serving-men struggling with a hag dressed all in armour. Behind her came eight others. And their eyes, from between the bars of their helms, shone with a horrible red fire, and from each point of their armour sparks flashed, and the swords in their grisly hands gleamed with a blue flame, so fierce and so terrible that it scorched the eyes to look upon them. But Perceval dashed upon the foremost witch, and with his sword beat her with so great a stroke that she fell to the ground, and the helm on her head was flattened to the likeness of a dish. When she fell, the light of her eyes and her sword went out, and the armour all seemed to wither away, and she was nothing but an old ugly woman in rags. And she cried out: 'Thy mercy, good Perceval, son of Evroc, and the mercy of Heaven!' 'How knowest thou, hag,' said he, 'that I am Perceval?' 'By the destiny spun by the powers of the Underworld,' she said, 'and the foreknowledge that I should suffer harm from thee. And I knew not that thou wert here, or I and my sisters would have avoided thee. But it is fated,' she went on, 'that thou come with us to learn all that may be learned of the use of arms. For there are none in Britain to compare with us for the knowledge of warfare.' Then Perceval remembered what he had heard the trolls--the people of the Underworld--say, though he had not understood their meaning. 'The stainless knight,' they said, 'shall gain from evil greater strength, and with it he may confound all evil.' 'If it be thus fated,' he said, 'I will go with thee. But first thou shalt swear that no evil shall happen to the lady of this castle nor to her daughter, nor to any that belong to them.' 'It shall be so,' said the witch, 'if, when the time comes, thou art strong enough to overcome my power. But if thou failest, Angharad is mine to do with as I will.' Then Perceval took leave of the lady of the Castle of Weeds, and of Angharad. And the lady thanked him with tears for saving their lives, but the girl was cold and scornful and said no word of thanks. Then Perceval went with the witches to their Castle of Glaive. He stayed with them for a year and a day, learning such knowledge of arms, and gaining such strength, that it was marvel to see the feats which he performed. And while he lived with them they strove to bend him to their wills, for they saw how great a knight he would become in prowess and in knightly deeds. They tempted him every hour and every day, telling him what earthly power, what riches and what great dominions would be his, if he would but swear fealty to the chief witch, Domna, and fight for her against King Arthur and his proud knights.