Summary: In 1619 Joseon, Lee Sungmin and Jo Kyuhyun are two spies for a Left-wing rebellion faction in the heart of Hanyang, led by Lee Youngwoon, Sungmin's father. However, what everyone does not know is the feelings they developed for each other in the four years of their training in the boarding academy, prior to their entrance to the Royal Palace. Now that Sungmin is one of the King's concubines, and Kyuhyun works in the Ministry of Defence in order to infiltra