As the time draws near for Gawain to leave the court in search of the Green Knight, the court is dishearted because they think Sir Gawain will not return. Aware that death may meet him, Gawain seeks shelter in a castle which turns out to be the Green Knight, tries to seduce Sir Gawain three times, while her husband is hunting.

Sir Gawain does not give into her seduction, and as a result, his life is spared when he encounters the Green Knight. As part of the test, the Green Knight asks Gawain if they could exchange their earnings for a day. Gawain gives the Green Knight a kiss for every one he has received, but does not give up the green belt, or girdle, the lady has given him, telling Gawain it will protect his life. The Green Knight nicks Sir Gawain's neck because he has lied about the belt, and Gawain, chastened and wiser, returns to Arthur's court.