Kim Tae Hyun is a promising young surgeon, but his finances take a dive when his sister's health condition requires costly dialysis treatments. When Tae Hyun subsequently falls into a vicious cycle of debt, he assumes the alias of "Yong Pal" and begins making house calls for criminals who are willing to pay top dollar. Complicating things further, Tae Hyun gets involved with Han Yeo Jin, a comatose patient at the hospital.

The story of Joseon's tyrant king Yeonsan who exploits the populace for his own carnal pleasures, his seemingly loyal retainer who controls him and all court dealings, and a woman who seeks vengeance.