He's a young ambitious King of mid-era Jeseon who went ballistic and over the edge from intense power struggle at the palace especially over the guilt for killing the rightful young heir brother. His dark mood, violence drive, and hatred made him enemies from all sides - he died from poison given by his most loyal and trusted minister. Such a tragic ending from a young King, there's no farewell, just died sad, scare, betrayed, in the beach alone. Warrant he's mentally sick and murderous he's still a King that demand utmost respect. Meanwhile a clown brought in to cover the absent King from duty, his job was to be poisoned and killed by the King's enemies - he's to become a substitute of King while the real one hide for his mental health. Not just he strives but also win the trust of many especially the queen as she started to fall in love to...the fake King - the Clown. He's constantly need advise from Chief Secretary, as an uneducated clown he knew nothing about politic, intrigue, people surround him, or read Hanja. He survive the ordeal intrigue around the palace, his heart is for the people, he makes right decisions with the advise from Chief Secretary.
The Dowager Queen wants him die for vengeance of her killed-young son (legitimate heir who's being killed by the real King), the Left State Counselor also wants him die because of greed and power.

While the King is vibrant and full of vitality, the Queen is kind of slow. The romance isn't appealing, I think the Queen spoiled it by acting too gloomy - she has to be forced to smile by a wish. If she's in love,her eyes says otherwise...her sad face isn't radiant like someone in love and she loves to be woo. She's 'cold' according to the real King (rightful husband)...but since the clown is good in wooing her...she felt for it. Well, when she finally find out about the secret, she's pissed.

I love Yeo Jin-Goo's acting. He can act as crazy maniac King and also as a tender heart-sweet gentle fake King. The loyal Chief Secretary is the main instigator of all...he loyalty to his King...he wants the King to love the people. He's the one who kills the young heir future King and kills the legitimate King..to choose fake King clown to ascent the throne. How twisted is his mind; he's wise, kind, considerate, but he also has 2 royal blood in his hand. I love Eunuch Jo - he's a good man - he tries to separate two lovebirds as morally they aren't truly husband & wife or love affair between a low born clown with high born noble Queen. Beside the Queen, I don't like Dal-lae character, sister of the clown, she'd be the dead of him.