"Swiftly, he slashed at the naked neck; the sharp of the battleblade shattered asunder the bones" (Line 149-150)
Sir Gawain Chops off The Green Night's Head, but he survives.
"Gawain leaves on his quest to find the Green Chapel and fulfill his pledge. After riding through wild country and encountering many dangers, he comes upon a splendid castle" (Line 185-190)
Sir Gawain sets out through the wilderness in search of the Green Chapel. He happens upon a castle, where he is only allowed to stay if he gives the lord everything he acquires throughout the day, in exchange for the game the lord hunts.
The first day, the Lord's wife gives Gawain a kiss while the Lord is hunting doe, so Gawain gives the Lord a kiss in return, and the 2nd day, Gawain gets 2 kisses from the wife, and returns 2 kisses to the Lord.
"While the Lord is out hunting, the lady attempts to seduce Gawain." (Line 187)
"And she pressed the sash upon him and begged him to take it, And Gawain did, and she gave him the gift with great pleasure" (Line 232)
However, on the third day, the wife gives Gawain her "magic green girdle" along with 3 kisses. Gawain hides the girdle from the Lord and keeps it for himself.
"Quickly then the man in the green made ready, Grabbed up his keen-ground ax to strike Sir Gawain"(Line 241).
Gawain leaves the castle and finds the Green Cavern, and confronts the Green night.
While in the cavern, the Green Night fakes 2 blows to Gawain's neck, before finally drawing blood on the third. He explains how he was also the Lord, and that he hit Gawain for not being honest and giving him the girdle.
"My wife’s advances, for I myself arranged them. It was I who sent her to test you " (Line 339).