In the series "Ghost Doctor," the focus is on a talented but arrogant cardiologist named Cha Young Min. After an unfortunate accident, his spirit leaves his body... and as a result of a mysterious incident, it possesses his shy colleague. Now, a genius sociopath and a timid neurotic coexist in one body. However, the unwelcome "guest" is unable to fully take control. He has to collaborate with the bungling colleague in order to save as many patients as possible.