A historical drama about the secret surrounding Crown Prince Sado’s death. This drama takes place during King Yeongjo’s (Han Suk-kyu) reign where his son, Crown Prince Sado (Lee Je-hoon) is forced to kill himself. Despite Yeongjo’s effort to change Sado, he has no choice but to order the death of Sado due to his mental instability, excessive violence, and sexual assaults. This drama will tell the discovery of the truth behind the mystery surrounding Sado’s death.