The Green Knight stars Dev Patel as Gawain, the nephew to King Arthur who ruled over the Round Table. On Christmas, a dark figure shows up to the Round Table and says he is The Green Knight. He presents a challenge to the Knights of the Round Table to attack him, and if they land any blow on him, they must come visit him one year later so that he can return that same blow to them. Basically, if they strike his hand, he gets to strike their hand back next Christmas. Gawain decides to accept the challenge and decides to chop off The Green Knight's head. To Gawain's surprise, The Green Knight picks his head back up and ride away. A year passes and now Gawain must go meet The Green Knight as is required.
The rest of the film is basically of Gawain's journey. I fully expected there to be much action and battles on the long road to a Chapel where The Green Knight is said to be waiting for him. However the story doesn't have much action at all. There are no epic battles, or fights. There is some light horror and suspenseful events, but nothing really happens significant at all in my opinion. I found the film to be a bit of a let down. A film set in Medieval Times with no epic battles? Not my cup of tea!