The Vampire Affair

Much creepier than I expected. Lots of somewhat accurate Dracula (the real one) lore.
Also, Napoleon meets with a real life person who is perfect for this book.
It's in the library scene, if you don't recognize the person, look him up.
His appearance in the book was delightful.
The characters sound like themselves and the plot is very much something that would have been on the show.
Long out of print, you might be able to find some of these books on abebooks.com (I am just a happy customer)