The Stuart Horten series does not have a new book coming out soon. The latest book, Horten's Incredible Illusions (Book 2), was published in September 2012.
The first book in the Stuart Horten series, Horten's Miraculous Mechanisms, was published in April 2012.
The Stuart Horten series primarily falls into the Mystery genre. This middle grade series was written for ages 8-12, but can be enjoyed by older readers as well.