Low-level Wagner without the music.
"If they be two, they are two so
As stiff twin compasses are two . . . ." John Donne
Tristan & Isolde is low-level Wagner without the music, a fairly-faithful rendition of the classic story of a young hero, Tristan (James Franco), asked by Cornwall's fifth-century King Mark (Rufus Sewell) to win the hand of the Irish king's daughter, Isolde (Sophia Miles), for marriage.
Tristan and Isolde, of course, fall in love, and begin a process that might remind you of Romeo and Juliet--star-crossed, nurse, and all that. But then, the story in all its mutations, has been around for quite a while, most famously morphed into Arthurian romance and scores of films. This version is unremarkable next to many of those predecessors.
Although James Franco's Tristan is more underwear model than warrior and Sophia Miles more Bridget Jones than queen, the costumes, supporting cast, and sets are so good I was tempted to give it an above average grade. But then I remembered lines such as "With every look he gives you I get sicker and sicker," and I got sick. I became even more nauseated when Isolde quoted John Donne, an early seventeenth-century poet and a considerable anachronism unjustified by any other I could see in this film.
Visually Tristan & Isolde is often a stunner, thanks to cinematographer Arthur Reinhart's period-heavy atmosphere. But then most of these cinematic historical epics are now regularly gorgeous, probably because the visuals can hide deficient screenplays.
If you've just read the Tristan in your lit course, this is the film for plot but not for language. For good old naughty pleasure, see The Graduate--a more pleasant dose of the scarlet A.