There are 4 books in the Professor Sophie Knowles series.
The Professor Sophie Knowles series does not have a new book coming out soon. The latest book, The Quotient of Murder (Book 4), was published in October 2019.
The first book in the Professor Sophie Knowles series, The Square Root of Murder, was published in August 2019.
The Professor Sophie Knowles series primarily falls into the Cozy Amateur Sleuth Mystery genre.