Then Sir Gawaine and Sir Ewaine were very much astonished that any knight should lie beneath so strange an obligation as that--to defend those who assailed his shield--and they besought Sir Marhaus to tell them why he should have been obliged to fulfil such a pledge. So Sir Marhaus said, “I will tell ye. The case was this: Some whiles ago I was travelling in these parts with a hawk upon my wrist. At that time I was clad very lightly in holiday attire, to wit: I wore a tunic of green silk, and hosen one of green and one of white. And I had nothing upon me by way of defence but a light buckler and a short sword. Now, coming unto a certain stream of water, very deep and rapid, I perceived before me a bridge of stone crossing that stream, but so narrow that only one horseman might cross the bridge at a time. So I entered upon that bridge and was part way across it, when I perceived a knight in armor coming the other way. And behind the knight there sat upon a pillion a very fair lady with golden hair and very proud of demeanor. Now, when that knight perceived me upon the bridge, he cried aloud, ‘Get back! get back! and suffer me to pass!’ But this I would not do, but said, ‘Not so, Sir Knight, for, having advanced so far upon this bridge, I have certes the right of way to complete my passage, and it is for you to wait and to permit me to cross.’ But the knight would not do so, but immediately put himself in posture of offence and straightway came against me upon the bridge with intent either to slay me or to drive me back unto the other extremity of the bridge. But this he was not able to do, for I defended myself very well with my light weapons. And I so pushed my horse against his horse that I drave him backward from off the bridge and into the water, whereinto the horse and the knight and the lady all of them fell with a terrible uproar. “At this the lady shrieked in great measure and both she and the knight were like to drown in the water, the knight being altogether clad in armor, so that he could not uplift himself above the flood. Wherefore, beholding their extremity, I leaped from off my horse and into the water, and with great ado and with much danger unto myself, I was able to bring them both unto the land.