There are 2 books in the Mrs. Hudson and Mary Watson Investigation series.
The Mrs. Hudson and Mary Watson Investigation series does not have a new book coming out soon. The latest book, The Women of Baker Street (Book 2), was published in January 2017.
The first book in the Mrs. Hudson and Mary Watson Investigation series, The House at Baker Street, was published in February 2016.
The Mrs. Hudson and Mary Watson Investigation series primarily falls into the Mystery genre.