It's a story I've known, from various retellings, for decades.

And certainly some elements of The Green Knight will be familiar to anyone steeped in Arthurian lore. Other elements are ... perhaps "odd" is the right word, although I'm sure the director would prefer I use "surreal." In any case, this new movie adaptation of the ancient tale seems unsure if it's going for epic or arty, and that dichotomy leaves the movie on uneven footing.

As Gawain, Dev Patel gives a strong performance. His journey falls somewhere between glory and squalor, and Gawain -- as yet untried and unknighted -- is equal parts brave, ambitious and anxious. No complaints about Patel's work here.

Special nods, too, go to Joel Edgerton, who himself played Gawain in 2004's King Arthur, as the mysterious Lord, and Alicia Vikander, who shoulders two roles: Gawain's lover, a commoner with great aspirations, and the equally mysterious Lady who, with the Lord, provides Gawain with a pivotal encounter on his quest. Also of note, Erin Kellyman as the haunting Winifred, another test along Gawain's path.

Written and directed by David Lowery, The Green Knight is more art than action, which in itself isn't the problem. (Assuredly, many people seeing the film will expect some swordplay in a King Arthur story, but there's actually very little. In fact, for reasons unclear, the title character, after freeing himself from his bonds after being robbed on his journey through the forest, leaves his valuable sword behind and trudges onward unarmed.)

Key figures from Arthurian lore are present, but mostly in supporting roles; in fact, characters including Arthur, Guinevere, Merlin and Morgause are never named in the movie, appearing in the credits simply as King (Sean Harris), Queen (Kate Dickie), Magician (Emmet O'Brien) and Mother (Sarita Choudhury). None of them do much of note in the movie, although Harris does a good turn as a good and noble king who, after a life of action and glory, is now old, feeble and desirous of little more than family, and a good story to pass the time. The Mother, who apparently becomes her sister Morgan le Fey in Lowery's interpretation, works various magics throughout the movie, but it's never clear what she's doing, or why.

No, this is Patel's movie, he's almost always on screen -- often alone -- as he struggles to keep his fateful appointment with the mysterious Green Knight (Ralph Ineson) who interrupted the court's Christmas celebrations with a deadly challenge. Gawain's journey to fulfill his quest is magical and weird, at times apocryphal and on occasion dreadfully dull. Like I said, this isn't an action movie.

In fact, at times the movie feels like it wants to be a horror film, when it grows up, but it never achieves true horror -- just discomfort and unease. The cinematography ramps up the atmosphere by drenching scenes in mist and darkness, making it at times hard to see what's going on.

The score, by Daniel Hart, is full of bombast and dissonance. It certainly holds your attention, sometimes painfully so, and at times it overwhelms the dialogue.

I went to see this movie with high hopes and great expectations. Unfortunately, it tries so hard to be artistic, it forgets to be a good film. The end result is a visual spectacle that's needlessly obtuse, with an ending borrowed heavily from The Last Temptation of Christ.

Oh, and what's the deal with the bald naked giants?