Wherefore if it will please you to read that which is hereinafter set forth, you will be told of how Sir Launcelot slew the great Worm of Corbin; of the madness that afterward fell upon him, and of how a most noble, gentle, and beautiful lady, hight the Lady Elaine the Fair, lent him aid and succor at a time of utmost affliction to him, and so brought him back to health again. And you may herein further find it told how Sir Launcelot was afterward wedded to that fair and gentle dame, and of how was born of that couple a child of whom it was prophesied by Merlin (in a certain miraculous manner fully set forth in this book) that he should become the most perfect knight that ever lived and he who should bring back the Holy Grail to the Earth.