I feel a little weird about giving this book (and its sequel) 5 stars, because they are not, and do not aim to be, Great Literature. This book certainly does not have the depth and layers of Eco's 'The Name of the Rose,' although it shares a similar atmosphere. However, for sheer entertainment value - I just love Berg's writing, and this is definitely one of her best.
It's a well-crafted genre mystery, with wizards.
Intrigue and plot twists abound, and there a lots of clues to put together and figure out.
The atmosphere is an enjoyable pseudo-Renaissance fantasy world, and the protagonist is a librarian (yay librarian heroes, even if my one quibble is that there could have been a bit more actual librarianship in the book!)
The librarian in question is a distant cousin of the king, and is summoned to court to secretly investigate a failed attempt on the king's life. The queen is suspected; the king believes her innocent... but will the investigation clear her name, or uncover layers of conspiracy and shady dealings?