The Twelve Books of Christmas by Kate Carlisle
I've read a couple of the previous Bibliophile Mysteries and enjoyed them well enough, so since I'm a sucker for Christmas cozy, I picked up The Twelve Books of Christmas. This time around Brooklyn gets a call on Christmas Eve from her good friend Claire, who is in Scotland. Claire is preparing to marry Cameron, a castle laird, on New Year's Day and wants Brooklyn and Derek to be there. So the couple, along with Brooklyn's parents, fly to Scotland. Claire also hopes that while she's there Brooklyn will help solve a mystery- a dozen Christmas-related books, some quite valuable, have gone missing from the castle library.
Of course, there's trouble. Most of the women in town, including the castle's new librarian, seem to be anti-Claire. Then, Brooklyn and Derek find a dead body in one of the castle's closets. They, of course, have to investigate the murder in addition to the missing books - which may or may not be...