It's a snowy Christmas morning in the kingdom and Essel, a worker at the bawdy house,
wakes up her client Gawain with a bucket of cold water. When Gawain realizes he overslept,
he rushes out of the building because he needs to get ready for the big Christmas banquet his uncle
the king will be throwing later. When he arrives at the castle, Gawain tells his mother he was in
church all night, but she doesn't believe him. Gawain notices his mother isn't dressed for the
party and she explains she hasn't got the guts for it this year, but she wants him to go and
have fun. As soon as Gawain leaves, his mother meets with her maids and she blindfolds her eyes
to begin a special ritual during which she writes a letter with a green seal on it. At the party,
the king invites Gawain to sit next to him because he's family. The king wants to hear
some stories from him but Gawain doesn't have any, so the queen tells them he'll get his own
stories when he becomes a legendary knight like those at the table. This means a lot to Gawain
because he's always wanted to be a knight. While Gawain's mother burns the letter she wrote and
the ashes make a sprout appear, the king begins giving a speech, only to be suddenly interrupted
by a tree-like person known as the Green Knight. The knight presents a letter with a green seal,
and when the queen breaks that seal, she becomes possessed by the Green Knight and begins reading
the letter with his voice. The Green Knight wants to play a Christmas game in which one of the
king's warriors tries to land a blow against him. If that man succeeds, he'll win the Green Knight's
axe, but he also must go to the Green Chapel a year from now to allow the Green Knight to return
the same blow. When the queen finishes reading the letter, it lights itself on fire, and the
queen falls down with dizziness. The king's too old to accept the challenge and he invites any of
his knights to do it, Gawain comes forward ready to prove himself. He doesn't have a sword though,
so the king gives him his own, reminding Gawain that it's just a game. Gawain is ready to fight,
but the Green Knight shocks him by putting down his axe on the floor, which causes moss to appear
on the stones. Then the Green Knight kneels and offers his neck, so Gawain lowers his sword,
causing the knight to lose his head. Gawain thinks it's all over, but as soon as he turns around,
the Green Knight rises and picks up his head, which reminds Gawain he must come to see him in
a year. Then the Green Knight leaves, and after a moment of awkward silence, everyone celebrates
Gawain's victory. Gawain returns the sword to the king and puts the axe away while his mother falls
to her knees, tired but pleased with herself. Almost a year later, the story of Gawain's
victory is told to the kids through a puppet show, and they show the ending of the second meeting as
rather tragic for their hero. Essel teases Gawain for becoming a legend in town and Gawain hates it,
but he still accepts to pose for a very bright portrait. In the evening when Gawain goes to
the local tavern, the drunkards talk of the Green Knight story, but they also mention a rumor about
Gawain's mother being a witch, so Gawain beats him up for his insolence. When he returns home,
he's surprised to see the king is there with his mother. The king reminds Gawain that Christmas is
around the corner, and when Gawain reminds him he said it was a game, the king points out it's
still incomplete. Gawain doesn't believe the Green Knight will be waiting for him,
but the king gently caresses Gawain's face and tells him to go anyway. When the first snow falls,
preparations for Gawain's trip begin. The queen and king take a shield to the church to
be blessed, the axe is retrieved from its box, and Gawain's mother makes a special green girdle with
a rune hidden inside. Essel doesn't want Gawain to leave, but Gawain explains he gave his word. When
Gawain is about to leave, his mother gives him the girdle and asks him to wear it all the time
because it'll protect him from any harm. Gawain travels alone and only stops to camp at night,
and to feel less lonely, he grabs the bell Essel gifted him and thinks about their last chat. Essel
had admitted to having feelings for him and asked him to make her his lady, but Gawain disappointed
her by not giving her an answer. The next day, Gawain reaches a crossroads intersection and
chooses a path by instinct. He begins to cross the woods and notices a fox running nearby, there's
also a body against a tree. Moments later, Gawain ends up on an abandoned battlefield. There he
finds a young scavenger who explains he's looking for his brothers' bodies. When Gawain mentions the
green chapel, the boy gives directions and asks for a reward, so Gawain tosses a coin at him.
Gawain stops by the stream to let his horse dress then takes the path through the forest that the
scavenger mentioned, but after a few steps in, he ends up cornered by two thieves. They grab him and
hold him down to present him to the scavenger, who reveals leading him here was a plan to rob him.
The boy teases Gawain with his knife and takes the girdle before the other two thieves tie him up,
leaving him on the ground while they go through his things. The scavenger breaks the shield,
and when he finds the axe, he's so impressed that he takes it away on the horse as his companions
follow him, leaving the other things behind. A few moments after the thieves are gone, a skeleton
appears on Gawain's spot, but this is actually a vision he's having of his own death. Refusing
to die in such a pathetic way, Gawain drags his body through the ground like a worm and reaches
for his sword, which he uses to cut off the ropes but also accidentally hurts him in the process.
Once he gets back his things, Gawain runs through the forest and gets lost. By the time night falls,
he finds a lake, and he's shocked to see an abandoned house near the water. Gawain enters
the building and finds it empty, so he decides to sleep comfortably on the bed. Moments later,
he's woken up by Winifred, who wants to know why he's taken her bed. Gawain apologizes and explains
he's a traveler that lost his way, causing Winifred to mention she's lost something too. She
creeps Gawain out when she begins to move because she floats instead of walking, making Gawain
assume she's some kind of spirit. When they make it outside, Winifred explains that a lord came
to her house and try to take advantage of her, but because she resisted, he killed her, and now
her head is at the bottom of the lake. Winifred would like Gawain to retrieve her head, and when
he wonders what he'd get as a reward, Winifred expresses confusion at the request. Gawain
decides to do the right thing and jumps into the lake, where he begins hearing voices calling for
him. Suddenly the water turns red and Gawain finds the skull, so he quickly takes it before
going back to the surface. Winifred is gone, but the fox is there again, only to leave after it
confirms Gawain is fine. With the skull in hand, Gawain returns to the bedroom and finds Winifred's
skeleton on the bed, which causes the skull to become her actual head. Gawain drops it in shock
and hears Winifred tell him that the Green Knight is someone he knows before picking it up again,
causing it to turn back into a skull. Then Gawain reunites the skull with its body on the bed, and
at that moment the sun raises, revealing the Green Knight's axe waiting for him in the room. Gawain
continues his journey on foot carrying the weight of the axe. The fox seems to be following him,
and when Gawain stops at a cave to rest, the fox tries to enter it. At first Gawain tries to scare
it away, but since the fox insists, Gawain lets him share the cave with him. The next morning,
the two of them begin traveling side by side. After a few hours of walking, they reach the top
of a hill and Gawain trips, causing him to roll down to the bottom and almost lose Essel's bell.
Later, Gawain is so hungry that he eats the first mushrooms he finds, but they make him throw up and
hallucinate that his hand is covered by moss. Suddenly Gawain hears some thunder rumbling in
the distance, and when looks up, he sees a creepy person staring at him from afar. The next day,
Gawain and the fox keep on walking until the ground starts to shake, and that's how they
find a group of giants emerging from behind the hills. Gawain immediately runs to them and asks
to ride on their shoulders, but when one of the giants tries to pick him up, the fox growls at
them to keep them away. The giants respond by letting out a high-pitched noise and moving on,
so Gawain and fox take the opposite road. Hours later, Gawain is so tired that he falls to the
ground, not sure he can continue. Fortunately the fox finds a castle nearby, which inspires Gawain
to stand up and run to the doors to ask for help because he passes out. The next morning Gawain
wakes up on a beautiful bed while someone touches his forehead. At first he thinks it's his mother,
but after blinking he discovers it's the lord of the castle. The lord's a fan of Gawain's story and
tells him not to worry because it's still December 21st, meaning he has time to rest. Then the lord
takes Gawain to have breakfast and introduces him to his mother, who has the eyes blindfolded, and
his lady, who shocks Gawain because she looks just like Essel. Gawain kisses her hand and turns down
her invitation to stay a few days because he has to arrive at the chapel soon. The lord corrects
him and explains the green chapel is only a few hours from the castle, so Gawain can stay and rest
properly for a few days to then leave on Christmas morning. Gawain accepts to stay and wanders around
the castle, where he discovers the fox depicted in the paintings. He also finds a huge library and
learns the lady has read all the books, she's also written a few of them. As a token of her
appreciation, she gifts Gawain a gift and asks for a kiss, but Gawain only kisses her cheek. Then the
lady asks Gawain to sit for her so she can paint him, and using a trick of light, the lady creates
a very eerie portrait of Gawain upside down while he sits in the next room. When she finally shows
him the final product, the lady notices the bell Gawain carries around his neck and asks if it
was a gift from a loved one, but since he says no, she breaks the string and steals the bell.
Sometime later, the lord comes back from hunting and gifts Gawain the deer he killed. Both men go
back inside to have a drink and the lord surprises Gawain by promising he'll gift him his best hunt
every day, however in return Gawain must give him anything he receives from the castle. Gawain
doesn't understand how there can be something that doesn't belong to the lord already, but
the lord just says the castle works in mysterious ways. The lady cuts in to discuss the Green Knight
and how the greens of nature always find a way to grow back. While the lady continues to play
with her cards, the lord asks what Gawain wishes to gain from this whole deal, so Gawain explains
he wants enough honor to finally become a knight. When Gawain goes to get ready for bed, he receives
a visit from the mother, who touches his face and her own chest before leaving with no explanation.
The next morning, Gawain wakes up to discover the lady has been watching him sleep. She comes
closer to touch Gawain and wonders why he didn't come to her bedroom last night, Gawain explains
he wanted to but didn't do it because it wasn't right. Then the lady asks Gawain if he believes
in magic and reveals she has the green girdle, she even knows that it's enchanted to protect whoever
wears it. Suddenly the lady climbs on the bed and begins getting frisky with Gawain, asking him to
take the girdle from her as she helps him finish. Once he does, the lady lets him keep the girdle,
but she also leaves his own seed on his hand as she points out he's no knight. After she leaves,
Gawain is shocked to discover the mother has been standing there all along. Tired of these games,
Gawain decides to leave. In the forest, he finds the lord, who can tell Gawain received something
from the castle. In order to take it back, he kisses Gawain to make up for what he did with the
lady. Gawain pushes his hand away and announces he's living, so the lord opens his bag and reveals
his latest hunt: it's the fox, who thankfully is still alive. After a few hours of walking,
Gawain and the fox finds a stream surrounded by an orange fog. There's a boat on the water, but when
Gawain tries to approach it, the fox growls at him to stop him. Gawain is confused by this attitude
until the fox suddenly reveals it can talk and warns Gawain that there's no happy ending ahead
of him. The fox thinks Gawain should return home, so Gawain swings his axe at it to scare
the animal away for not being supportive. Gawain takes the boat down the steam and only comes back
to land when he finds a road marked by a cross. It only takes him a few minutes on foot to reach
the chapel, and inside he finds the Green Knight sitting at the altar, but he's asleep. Gawain sits
in front of him and after putting down the axe, he waits. On Christmas morning, the Green Knight
finally awakes. He grabs the axe and announces they'll finish the game, for which Gawain must
kneel to receive the same blow he threw last year. Gawain kneels as asked but when the Green
Knight raises his axe, Gawain's so scared that he flinches. The Knight teases him for it since
he had a whole year to be ready for this moment, thus Gawain takes a moment to gather courage and
asks him to try again. The Green Knight raises his axe once more, but Gawain still can't help himself
and moves away. He wonders if the game truly is just this, and when the Green Knight confirms,
Gawain kneels again, only to move away when the axe comes for him. Refusing to die so soon,
Gawain runs away, and as he crosses the forest he's surprised to find his horse. Sometime later,
Gawain returns to the city and reunites with his mother, who immediately takes care of his wounds.
Afterward Gawain visits Essel, who is sad to see her bell is gone. The two of them get frisky
together, but Gawain never takes off the girdle. A few days later, Gawain is called to the castle
because the king doesn't have much time left. With the last of his strength, the king finally knights
Gawain and gifts him his precious sword. After the king's death, Gawain becomes the new monarch,
which seems to have been his mother's plan all along. Nine months later, Essel gives birth to
Gawain's son. Gawain still doesn't marry her though, he just shows up to pick up the baby,
and he leaves after leaving some money for the bawdy house without caring about leaving
a devastated Essel behind. A year later, Gawain marries a noblewoman, and on their wedding night,
he doesn't allow her to take off his girdle. They fulfill their marital duties, but Gawain doesn't
find them as satisfying as it was with Essel. Years pass and the kingdom gets involved in a
war. Gawain decides to start training his child as a knight, but by the time the boy as soon as
the boy becomes of age, he dies in battle. The consequences of this war change the citizen's
opinions of Gawain and he becomes a hated leader that gets stones thrown at. Essel hates him even
more now because her son is dead, but at least the queen gives birth to a new heir. A few years
later, the castle is under siege, and Gawain is abandoned by everyone, including his own wife and
his mother. Alone with the eerie painting that has been hung straight, Gawain finally takes off his
girdle, which he has never taken off before. This causes his head to fall and the crown rolls away.
Suddenly Gawain blinks and finds himself in the chapel again, it turns out all he saw had been a
vision showing him the future he'd get if he runs away. The Green Knight raises his axe but Gawain
asks for a moment to take off the girdle, which should leave him vulnerable. Now Gawain can say
he's ready for real, and the Green Knight gently caresses his face, congratulating him for finally
being brave and keeping his word. Afterward the Green Knight tells him "now, off with your head".