This is a nice, light, easy read with some humor. Not Arthurian, but some of the characters are very interested in King Arthur and the archaeology of 5th century artifacts. The characters visit quite a few "Arthurian" sites like Cadbury, Glastonbury, and Cornwall.
I also read this book, because one of the characters is apparently modeled after Dorothy Dunnett's Francis Crawford of Lymond, whom I adore (the character AND the author!) and this character will return in some of the Vicki Bliss novels, which I plan to read.
Here's the blurb from the back cover.....
"For Jessica Tregarth, an unexpected invitation to visit her grandfather in England is a wonderful surprise -- an opportunity to open doors to a family past that have always been closed to her. But sinister acts greet her arrival. A stranger tries to steal her luggage and later accosts her in Salisbury Cathedral. Mysterious villians pursue her through Cornwall, their motive and intentions unknown. Jessica's only clue is an antique heirloom she possesses, an ancient ring that bears the Tregarth family crest. And her only ally is handsome gothic novelist David Randall -- her self-proclaimed protector -- who appears from seemingly out of nowhere to help her in her desperate attempt to solve a five hundred-year-old puzzle. For something from out of the cloudy mists of Arthurian lore has come back to plague a frightened American abroad. And a remarkable truth about a fabled king and a medieval treasure could ultimately make Jess Tregarth very rich...or very dead."