There are 4 books in the Nightshade Prequel series.
The Nightshade Prequel series does not have a new book coming out soon. The latest book, Shadow Days (Book 2.5), was published in December 2012.
The first book in the Nightshade Prequel series, Rift, was published in August 2012.
The Nightshade Prequel series primarily falls into the Fantasy genre. This young adult series was written for ages 12-17, but can be enjoyed by adults too.