The Whidbey Island series does not have a new book coming out soon. The latest book, The Edge of the Light (Book 4), was published in August 2016.
The first book in the Whidbey Island series, The Edge of Nowhere, was published in September 2012.
The Whidbey Island series primarily falls into the Mystery genre. This young adult series was written for ages 12-17, but can be enjoyed by adults too.