While they yet talked, there entered the prison a damsel. She went up to the King at once, and said: "Knight, will ye undertake to fight in the cause of the lord of this castle?" "That I may not say," replied the King, "unless first I may hear what is his quarrel." "That ye shall not know," replied the damsel, "but this I tell you: if ye refuse, ye shall never leave this dungeon alive, but shall perish here miserably." "This is a hard case," said the King, "that I must either die or fight for one I know not, and in a cause that I may not hear. Yet on one condition will I undertake your lord's quarrel, and that is that he shall give me all the prisoners bound here in this dungeon." "It shall be as ye say," answered the damsel, "and ye shall also be furnished with horse and armour and sword than which ye never saw better." Therewith the damsel bade him follow her, and brought him to a great hall where presently there came to him squires to arm him for the combat; and when their service was rendered, the damsel said to him: "Sir Knight, even now there has come one who greets you in the name of Queen Morgan le Fay, and bids me tell you that the Queen, knowing your need, has sent you your good sword." Then the King rejoiced greatly, for it seemed to him that the sword that the damsel gave him was none other than the good sword Excalibur.
When all was prepared, the damsel led King Arthur into a fair field, and there he beheld awaiting him a knight, all sheathed in armour, his vizor down, and bearing a shield on which was no blazonry. So the two knights saluted each other, and, wheeling their horses, rode away from each other some little space.
Then turning again, they laid lance in rest, and rushing upon each other, encountered with the noise of thunder, and so great was the shock that each knight was borne from the saddle. Swiftly they gained their feet, and, drawing their swords, dealt each other great blows; and thus they contended fiercely for some while. But as he fought, a great wonder came upon Arthur, for it seemed to him that his sword, that never before had failed him, bit not upon the armour of the other, while every stroke of his enemy drew blood, till the ground on which he fought was slippery beneath his feet; and at the last almost his heart failed within him, knowing that he was betrayed, and that the brand with which he fought was not Excalibur. Yet would he not show aught of what he suffered, but struggled on, faint as he was and spent; so that they that watched the fight and saw how he was sore wounded, marvelled at his great courage and endurance. But presently, the stranger knight dealt the King a blow which fell upon Arthur's sword, and so fierce was the stroke that the blade broke off at the pommel. "Knight," said the other, "thou must yield thee recreant to my mercy." "That may I not do with mine honour," answered the King, "for I am sworn to fight in this quarrel to the death." "But weaponless thou must needs be slain." "Slay me an ye will, but think not to win glory by slaying a weaponless man."