Since I enjoyed The Orphan Queen books so much I knew I had to read this novella as well. The Hidden Prince is told from Prince Tobias's perspective and is a sort of origin story for the vigilante Black Knife. We get an insight into Tobias's early life.
After being kidnapped Tobias is forced to live a pretty sheltered life by his father. He is struggling with being who he wants to be and who he is expected to be.
We also get to see a bit of Lady Chey and Meredith and, of course, his cousin James. It was great to see James again and his relationship with Tobias before becoming his bodyguard.
I highly recommend this to be read after The Orphan Queen. There is also a 2 chapter excerpt for the next (and final) book, The Mirror King.