MurderByDeath
Shadow of Night takes place primarily in 1591, but the author doesn't get bogged down in too much historical detail. Most of the detail is in passing observations made by Diana, so it's easy for non-history lovers to take in. I loved the Libri Personæ at the back of the book, detailing the characters, and noting which ones were known to actually exist at the time. I think it makes the fiction that much more fun to read when notable figures in history are interwoven into the story.
There are a couple of plot lines that run through the book, and there were a few times it felt like one or the other might be getting a bit lost. Most of the questions raised in the book are answered by the end, with one or two hanging out there to be answered in the third book. But what I really appreciated was this book felt like it ended - no gigantic cliff-hangers. There are upcoming events and confrontations that you know will appear in the third book; major events that need to be explained, but Shadow of Night, I think, has enough of an ending that early readers like myself won't get too irritated with having to wait another year/18 months for the final book. I was able to close the book at the end with a sense of satisfaction, not frustration.
NB: I loved the last chapter - made me smile.