The Ghost Manuscript by Kris Frieswick
This was an excellent mix of thriller, history, antiquities, libraries, and action-adventure. I wasn't sure what to expect when I started this, after picking it up at the library on a whim. Carys Jones is a rare book authenticator who works for an auction house. She's worked on tracking down British Dark Age manuscripts for John Harper, a super rich man who has created a one of a kind library at his estate. Harper has been committed to an insane asylum because he's been hallucinating and insisting he's talking to a monk who was the personal holy man to the man known today at King Arthur. Carys has been called in to look over the collection and to catalog it and prepare it for sale. Harper's son JJ is selling the library, along with the estate. Carys thinks she's just there to prepare the library for sale, but her meeting with Harper reveals something a bit too hard to believe: a rare manuscript written by a monk telling the true story of ...