Sang-hyun is a priest working for a hospital. He selflessly volunteers for a secret vaccine development project intended to eradicate a deadly virus. However, the virus eventually takes over the priest. He nearly dies, but makes a miraculous recovery after receiving an accidental transfusion of vampire blood. He quickly realizes his sole reason for living involves taking the pleasures of the flesh. He struggles to control his insatiable thirst for blood until a love affair unleashes his darkest desires in deadly new ways.