This as a vampire story for grown-ups. The cheesiness and eye-rolling improbability is kept to a minimum. The story is presented within the context of the academic study of history and I found most of information given about Vlad III fascinating. I did a little bit of research on my own to find out what was true and what was fictional. The plot itself is fast moving enough, but it does slow down significantly when the historical lectures are presented.
For me, the only distractingly improbable part is how most of the story is told. It is told mostly through written letters that are so detailed that the writers would have needed weeks (or at least days) to complete them, a photographic memory, and to believe that the minutiae of every setting is relevant. Also, the letters are somehow written without anyone noticing and often when the authors fear that they are in mortal danger. That vampires exist at all, I can handle, but who goes about describing every knickknack in someone’s living room while being hunted by Dracula?
Although this is mostly plot-driven and the plot itself is impressively engineered, I would have liked more character development. We often mention it when male authors don’t write women well. In this book, Kostova is a female author who doesn’t write her men well. There is nothing bad about the men (except the ones who are straight-up villains and are meant to be bad). The heroic male characters aren’t dumb or incompetent. They are all brilliant academics, but they only vary in appearance, age, and circumstance. The voices of these men also blend together to such an extent there were times when I momentarily forgot who was speaking, especially during the long lectures.
Even so, I still found this book to be fun, romantic, gothic, and all of the stuff you want in a vampire novel.