There are 2 books in the On His Majesty's Secret Service series.
The On His Majesty's Secret Service series does not have a new book coming out soon. The latest book, The Duke's Dangerous Kiss (Book 2), was published in January 2019.
The first book in the On His Majesty's Secret Service series, The Duke Who Loved Me, was published in November 2018.
The On His Majesty's Secret Service series primarily falls into the Historical Romance genre.