[1][2][3][4] The period drama explores the conflicted and ultimately tragic relationship between King Yeongjo and his son, Yi Sun (Crown Prince Sado).

Shrewd Yeongjo wants to strengthen royal power, but passionate and idealistic son dreams of equality and a status-free society.

[2] According to historical documents, primarily those written by his wife in the Memoirs of Lady Hyegyeong, Sado was insane and violent, and was a serial rapist and killer.

So Yeongjo issued a royal decree that ordered Sado to climb into and be sealed within a large wooden rice chest on a hot July day in 1762.

In the 19th century, conspiracy theories arose that Sado had not been mentally ill, but had pushed for revolutionary changes and thus his political opponents had framed him for crimes he did not commit.