As Gawain lies in bed on New Year’s morning, the wind wails outside and snow threatens. He gets ready while it's still dark. Despite his worries, he dresses in armor that is shined as brightly as it was when he left Camelot, and he wraps the green girdle around his waist. He mounts Gringelot, thanks and blesses the court and rides out with his accompanying servant, across mountains and brooks, a long weary way before sunrise.
The servant brings him close to the Green Chapel but stops before reaching it, saying that he will not accompany Gawain to the doomed destination. He warns Gawain of the giant he will find at the chapel, of his super human strength, and says he will be surely killed if he chooses to go. He begs Gawain to turn back, and says that he will not tell anyone if Gawain runs. But Gawain explains that he cannot bear to be a coward and must go on. The servant reminds him that facing the Green Knight is certain death, and hurries away.
The plot gives Gawain many chances to back out of the final journey to the chapel but in the end even certain death and all the reputation that the Knight has built up over the course of the year can't defeat Gawain’s will to not be a coward. It is also an important moment in Gawain’s individual journey, now left alone, we have the opportunity to observe Gawain’s will away from the confines of either court. His reputation is safe no matter how he acts, and he acts courageously.
Now alone, Gawain steels his courage and continues on into the wilderness. He can see no chapel, only high banks of rock and cliffs that cast shadows on his path. He sees a grassy mound ahead but when he gets closer, he realizes that it is hollow like a cave. He thinks that if this is the chapel, it is a chapel that is home to the devil. He begins to believe the place is fitting for the Green Knight’s dwelling. Gawain readies himself with his sword and climbs to the top of the mound. Suddenly there is a loud noise. Gawain assumes it is the Green Knight. He summons his courage and announces himself, saying he has come to fulfill the agreement. A voice calls back that he will appear in good time.
Clarity and truth are difficult to find in the poem and the landscape around Gawain personifies this. Examples of obstacles, shadows and illusions fill this part of the poem, showing that Gawain’s journey has reached its peak and neither order nor religion seem to be there to help him now. When the expected signs of the typical Christian chapel do not appear, Gawain deals with it by assigning the mound to a hell-like category.
As Gawain waits, he hears the sharpening of a blade, which he knows is the sound of his own doom. The next moment, the Green Knight appears, wielding a huge new Danish axe. Gawain greets the knight with a bow and the knight welcomes him and praises him for his timeliness. The Green Knight then announces that the time has come for the exchange to be completed. Gawain bares his neck just as the Green Knight had done a year ago.
As Gawain waits for what seems like certain death approaching—first the sharpening blade, then the Green Knight himself—the connection to every man's eventual natural death once again becomes clear. All people must face this moment. Gawain does not run. And the Green Knight continues to treat this meeting like the fulfillment of a contract (and you could argue that each man has a contract with nature—to die).
The Green Knight makes ready to strike, raising the axe high, but as it descends, Gawain flinches slightly and the knight withdraws his weapon. He accuses Gawain of not living up to his reputation and boasts of superior bravery. Gawain assures him there will be no more flinching but says to strike swiftly so that he can meet his destiny, because, unlike the Green Knight, he will not be able to pick his head from the floor and walk away.
Gawain shows himself to be a human being by physically reacting to his fear of the axe stroke. His response to the Green Knight's mockery is an effort to protect his reputation—to act brave. But he does not see in himself the possibility of the miraculous or supernatural that is so evident in the Green Knight.
The Green Knight raises the axe again but this time halts its descent to praise Gawain for his lack of flinching. Gawain fiercely urges him to stop delaying and strike.
The Green Knight mocks Gawain's courage, as if that courage, so prized in chivalry, is not all it's cracked up to be.
The Green Knight is impressed by this ferocity and takes aim again, this time bringing the axe right down on Gawain’s neck. But the strike only nicks Gawain on the neck, and does not behead him. Seeing his own blood hit the snow but feeling himself alive, Gawain stands up to the Green Knight and defends himself with his shield. He says that he has fairly taken the promised stroke and that he will defend himself from any further attack, and invites the knight to fight.
Just as the contract with the Green Knight has brought him misery, now the contract frees Gawain – it is only now, after the structure of the game has been fulfilled and the return stroke completed that Gawain finds the bravery to stand up to the knight, knowing that within the rules of the game, he can now defend himself.
The Green Knight leans on his axe, states his admiration for Gawain's courage, and refuses the offer to fight. He explains how he has spared Gawain, saving him from the first two strokes in accordance with Gawain’s honest exchange of the lady’s kisses on the first two days of the hunt. The Knight explains that on the third day, Gawain was deceptive and hid the green girdle from his host, so received one nick from the axe. Gawain is shocked to realize that the Green Knight was in fact Gawain’s host from the castle and that his wife had been in on the game, tempting Gawain and reporting back to the Green Knight.
The Green Knight suddenly becomes non-threatening, almost avuncular, now that the game is over. Yet note that by the strict rules of the game, the Green Knight could have killed Gawain. Gawain both agreed to the rules of the beheading game, and broke the rules of the exchange of gifts. Yet the Green Knight, who throughout the poem had become connected also to natural death, did not kill Gawain. Instead, he acted with mercy, he did not follow the letter of the law, but rather gave Gawain the penalty he deserved for his failure—a mere nick. The Green Knight's actions here suggest that there is a miraculous force that can protect men from the pernicious effects of reputation (which is what made Gawain hide the fact that he was relying on the green girdle) and even from natural death: mercy, or divine love. The story can itself be read as a kind of endorsement of divine love, as opposed to the strict rules of divine law that are embodied in the complicated codes of chivalry. And not just any mercy or divine love—Christ's divine love. And, in fact, Christianity itself is often contrasted to Judaism, from which it emerged, as an evolution from a religion based on divine law to one based on divine love.
The Green Knight again praises Gawain, calling him the best and bravest of Arthur's knights. Gawain, ashamed at his failure to return the green girdle to his host, rushes to untie it from his waist and offers it to the knight. But the knight tells him that there is nothing left to repent – he has made an honest confession. Furthermore, the Knight tells Gawain to keep the green girdle as a token of their adventure, and to come feast with him the following New Year and reconcile with the lady who had tricked him.
The recognition of the mercy that has been extended to him makes Gawain ashamed, makes him truly repent of his sins in a way that his daily trips to confession never did. Gawain has now become in the eyes of his supernatural judge the bravest of knights, because he is the only one who has actually faced a real trial, in the real world. And while he did not necessarily overcome it cleanly, the value of confession and atonement for his sin is greater than his failings.
Gawain refuses the invitation but sends his wishes to both the old and the young ladies. He curses the deceitfulness of women, listing the important men of history that have been tricked by women, such as Adam, Samson, Solomon, and David, and comments that if those heroes could be tricked by women then he can forgive himself for being similarly tricked. Gawain does accept the green girdle, not for its material value, but to remind him of his weakness.
Continuing the poem's religious metaphors, the secret importance of women in the masculine world of the court is compared to Adam’s fall from grace because of Eve’s betrayal. The symbol of the green girdle has changed now, and is the first symbol with genuine meaning behind it—it becomes a symbol of Gawain's humility resulting from recognition of his own human failings, which has replaced his former reliance on reputation.
Gawain asks to know the real name of the Green Knight. The knight tells him it is Bertilak of Hautdesert. He explains that he has learned his supernatural skills from Morgan Le Faye, the old woman who dwelt at the castle with him. It was this sorceress who sent Bertilak to Camelot. Her reasons were to test the reputation of Arthur’s knights and to scare Guinevere to death with the gore of the axe stroke. Bertilak then tells Gawain that Le Faye is actually his aunt, Arthur’s half-sister. Bertilak once again invites Gawain to join him for the New Year's feast, but Gawain again declines, and the men kiss and part.
The revelations here connect the story more deeply to the traditional Arthurian legends, with the rivalry between Morgan Le Faye and Guinevere and the tangled blood relations. Yet Morgan Le Faye's goal was also explicitly to test the reputations of Arthur's knights, to see what was real beneath the reputation, and Gawain faced the test, even if (like any human) he did not pass it perfectly.
Gawain rides back across the wilderness and woods to Camelot, overcoming many adventures on the way. His neck wound heals and he enters Arthur’s court wearing the green girdle like a sash. He is greeted with joy and love. He confesses the whole tale and shows them his neck, pained by his shame in his own failure. He announces that he will wear the girdle forever, as the symbol of his failure. The king comforts Gawain and suggests that everyone in the court wears a band of green to show their love for him.
Gawain re-enters Camelot, that bastion of reputation, wearing the green girdle, the symbol of his failure and humility, for all to see. Put another way: Gawain has embraced his failure, he holds tight to his humility, because these are the things that make him human. And in so doing the Arthurian court rallies around him, showing a degree of compassion that was not evident earlier, and universally embracing this symbol of humility to temper their emphasis solely on following the "rules" of Christian chivalry. The green girdle has been added to the symbols of the pentangle, marrying the rigidity of the code with the more flexible and "real" virtue of humility.
The poet concludes by once again referencing the historic heroes that preceded the tale, reminding the reader that the story of Gawain and the Green Knight is one of the most marvelous in Arthurian times and recorded in the book of Brutus. The poet ends the list of heroes, and the poem, by praising Christ.