What is a brief summary of sir gawain?

Sir Gawain and the Green Knight follows a classic quest formula, with a knight receiving a challenge, going out on a journey to meet that challenge, and returning home to report on his quest.

At Christmas, a knight who is completely green rides into King Arthur's hall. The Green Knight proposes a game: Any knight brave enough to strike off the Green Knight's head may keep the Green Knight's ax, but that man must accept a return stroke in one year. Gawain accepts the challenge and cuts off the Green Knight's head. The knight picks up his severed head and leaves, telling Gawain to look for the Green Chapel.