Watch Secret Door

The King and the Prince both face tough decisions that will ultimately cost one of their lives.

The commoners' library is raided while the Prince's secret palace library and books are discovered.

The Noron sets out to discover why the Prince has been sending funds to the North.

On the eve of the new Queen Announcement ceremony, the Prince discovers a plot to assassinate the King.

The Noron set a new plan in action to oust the Crown Prince.

Prince Sado faces the fallout of allowing commoners to take the civil service exam.

King Yeongjo and Prince Sado clash over allowing commoners entrance to the civil service exam.

Prince Sado returns to the regency and sets out to make the country a better place for all classes.

Kim Taek sets a plan in motion to oust and replace Prince Sado.

In order to get his governing powers back, Prince Sado begins difficult negotiations with the Qing.

King Yeongjo strips Prince Sado of all governing power. Three years later, Prince Sado begins a secret plan beginning with taking Kim Taek as his new teacher.

King Yeongjo unleashes his punishment on the booklenders.

King Yeongjo appoints a new Prime Minister and sets out to enact new tax reforms while Prince Sado struggles with what to do about his father.

Prince Sado becomes suspicious of his father's role in the document.

Teacher Park Moon Soo makes a deal to try and save Prince Sado from prison.

Prince Sado is accused of murder.

Prince Sado seeks out the identity of the man Heung Bok's final royal painting.

Ji Dam hides out in a brothel while Prince Sado discovers the meaning behind Jung Woon's dying message.

With Ji Dam's help, Prince Sado delves deeper into the conspiracy behind Heung Bok's death.

Prince Sado succumbs to all evidence painting Heung Bok as a traitor, that is until Ji Dam approaches him with proof to the contrary.

Unsatisfied with the result of the investigation into Heung Bok's death, Crown Prince Sado re-opens the case, personally heading it himself.

Heung Bok's body is found and the conspiracy to cover-up his murder begins.

A document, thought long destroyed, tying King Yeongjo's ascension the throne to the Noron Faction, resurfaces. Crown Prince Sado disrupts the government by proclaiming the creation and distribution of books by commoners legal.