There are 3 books in the Randall Gatsby Sierra series.
The Randall Gatsby Sierra series does not have a new book coming out soon. The latest book, Kill the Hundredth Monkey (Book 3), was published in March 1995.
The first book in the Randall Gatsby Sierra series, What Rough Beast?, was published in September 1992.
The Randall Gatsby Sierra series primarily falls into the Mystery genre.