THEN there came Sir Kay, the Seneschal, unto King Mark, and there he had good cheer showing outward. Now, fair lords, said he, will ye prove any adventure in the forest of Morris, in the which I know well is as hard an adventure as I know any. Sir, said Sir Kay, I will prove it. And Sir Gaheris said he would be avised for King Mark was ever full of treason: and therewithal Sir Gaheris departed and rode his way. And by the same way that Sir Kay should ride he laid him down to rest, charging his squire to wait upon Sir Kay; And warn me when he cometh. So within a while Sir Kay came riding that way, and then Sir Gaheris took his horse and met him, and said: Sir Kay, ye are not wise to ride at the request of King Mark, for he dealeth all with treason. Then said Sir Kay: I require you let us prove this adventure. I shall not fail you, said Sir Gaheris. And so they rode that time till a lake that was that time called the Perilous Lake, and there they abode under the shaw of the wood.

The meanwhile King Mark within the castle of Tintagil avoided all his barons, and all other save such as were privy with him were avoided out of his chamber. And then he let call his nephew Sir Andred, and bade arm him and horse him lightly; and by that time it was midnight. And so King Mark was armed in black, horse and all; and so at a privy postern they two issued out with their varlets with them, and rode till they came to that lake. Then Sir Kay espied them first, and gat his spear, and proffered to joust. And King Mark rode against him, and smote each other full hard, for the moon shone as the bright day. And there at that jousts Sir Kay's horse fell down, for his horse was not so big as the king's horse, and Sir Kay's horse bruised him full sore. Then Sir Gaheris was wroth that Sir Kay had a fall. Then he cried: Knight, sit thou fast in thy saddle, for I will revenge my fellow. Then King Mark was afeard of Sir Gaheris, and so with evil will King Mark rode against him, and Sir Gaheris gave him such a stroke that he fell down. So then forthwithal Sir Gaheris ran unto Sir Andred and smote him from his horse quite, that his helm smote in the earth, and nigh had broken his neck. And therewithal Sir Gaheris alighted, and gat up Sir Kay. And then they yode both on foot to them, and bade them yield them, and tell their names outher they should die. Then with great pain Sir Andred spake first, and said: It is King Mark of Cornwall, therefore be ye ware what ye do, and I am Sir Andred, his cousin. Fie on you both, said Sir Gaheris, for a false traitor, and false treason hast thou wrought and he both, under the feigned cheer that ye made us! it were pity, said Sir Gaheris, that thou shouldst live any longer. Save my life, said King Mark, and I will make amends; and consider that I am a king anointed. It were the more shame, said Sir Gaheris, to save thy life; thou art a king anointed with cream, and therefore thou shouldst hold with all men of worship; and therefore thou art worthy to die. With that he lashed at King Mark without saying any more, and covered him with his shield and defended him as he might. And then Sir Kay lashed at Sir Andred, and therewithal King Mark yielded him unto Sir Gaheris. And then he kneeled adown, and made his oath upon the cross of the sword, that never while he lived he would be against errant-knights. And also he sware to be good friend unto Sir Tristram if ever he came into Cornwall.

By then Sir Andred was on the earth, and Sir Kay would have slain him. Let be, said Sir Gaheris, slay him not I pray you. It were pity, said Sir Kay, that he should live any longer, for this is nigh cousin unto Sir Tristram, and ever he hath been a traitor unto him, and by him he was exiled out of Cornwall, and therefore I will slay him, said Sir Kay. Ye shall not, said Sir Gaheris; sithen I have given the king his life, I pray you give him his life. And therewithal Sir Kay let him go. And so Sir Kay and Sir Gaheris rode their way unto Dinas, the Seneschal, for because they heard say that he loved well Sir Tristram. So they reposed them there, and soon after they rode unto the realm of Logris. And so within a little while they met with Sir Launcelot that always had Dame Bragwaine with him, to that intent he weened to have met the sooner with Sir Tristram; and Sir Launcelot asked what tidings in Cornwall, and whether they heard of Sir Tristram or not. Sir Kay and Sir Gaheris answered and said, that they heard not of him. Then they told Sir Launcelot word by word of their adventure. Then Sir Launcelot smiled and said: Hard it is to take out of the flesh that is bred in the bone; and so made them merry together.