Guinever's Gift, by Nicole St. John

At the turn of the century, Lydian Wentworth, after the death of her overbearing father, receives an invitation to visit the reclusive Arthuria-obsessed artist Charles Ransome. Charles is a family friend with whom her father mysteriously parted ways years before. In a whirlwind, they become engaged and maried. But things turn dark as Charles falls into an obsession with finding the grave of Arthur. The household as a whole goes to madness, murder, and dark secrets revealed. Melodrama ensues.

Not quite sure how this classic romance/mystery ended up on my YA reading list, but it was probably a mistake (perhaps a confusion with a similarly-title YA novel coming out in 2008). I found this older novel terribly overblown and pretentious (and more than a little bit silly). Probably better thought of in retrospect than in the actual reading. Avoid.