The Queen's Thief series does not have a new book coming out soon. The latest book, A Conspiracy of Kings (Book 4), was published in May 2017.
The first book in The Queen's Thief series, The Thief, was published in May 2017.
The Queen's Thief series primarily falls into the Action Adventure genre. This young adult series was written for ages 12-17, but can be enjoyed by adults too.