실력 있는 외과의사 태현은 돈을 벌기 위해 '용팔'이라는 이름으로 범죄자들을 몰래 치료한다. 어느 날 경찰이 들이닥쳐 자신을 찾던 와중에 VIP 병동에 갇혀 있는 여진의 존재를 알게 된다. 태현은 재벌가 상속자인 여진을 치료하면 돈을 좀 더 벌 수 있을 거라 기대하며 주치의가 된다. 하지만 시간이 지나면서 두 사람은 서로에게 빠져들고, 둘의 관계는 상대를 위해 위험도 무릅쓸 만큼 깊은 감정으로 발전한다.
He saves lives and tries to earn an extra buck every time. That's Tae Hyun, who also goes by Yong Pal at night. He treats VIP chaebol heirs in his day job in the hospital and treats criminals who need a second chance in life at night. He comes across a patient who is held captive in a VIP room named Yeo Jin. His initial urge to help her out leads him to have her as a source of income. After their business with each other, love seems to have filled the air. He doesn't get immediately how much trouble would come with loving Yeo Jin, an heiress of a hospital. The dispute leads to many deaths on their way, and they also fall in and out of love while at it. It seems like they would risk their lives for each other, but loyalties can change when family and money are now at stake.