Ji-sang is a doctor who fights for justice and sets out to protect the sanctity of human life -- despite being a vampire.

After learning the grave secret running through his veins, Ji-sang joins Taemin Cancer Hospital in an attempt to unravel the mysteries of VBT-01.

Ji-sang wows his coworkers with his surgical skills. The new director, Jae-wook, seems pleased with Ji-sang’s reaction to seeing a patient’s blood.

Ji-sang’s inhibitors are secretly switched. Jae-wook establishes the New Drug Development Headquarters and gathers patients for Ward 21A.

Ri-ta examines Ji-sang when he collapses after being injected with a drug by some mysterious men. Hyun-woo analyzes the contents of the injection.

Hyun-woo discovers that the injection is the same drug that killed Ji-sang’s mother. Ji-sang recovers and challenges the mysterious men to a fight.

Ji-sang learns the injection made the virus stronger. Ri-ta tells Chairman Yoo about the unusual atmosphere she felt at Ward 21A’s opening ceremony.

Ji-sang loses control when his inhibitors wear off. Ri-ta witnesses Ji-sang’s wound instantly heal. Ji-tae grows suspicious of Ward 21A.

Ji-sang and Ri-ta attend a seminar on Jeju Island. After hearing one of Ri-ta’s childhood memories, Ji-sang realizes she is the girl he once saved.

Ji-sang worries that Ri-ta is avoiding him. When Ji-sang’s thirst for blood increases, Jae-wook recommends he ingest special blood.

Ji-sang decides to resign from his post. The New Drug Development Headquarters quarantines a Ward 21A patient despite opposition from the doctors.

Hyun-woo analyzes the blood Ji-sang got from Jae-wook. Ri-ta witnesses Ji-sang’s superhuman power when he saves a patient from being hit by a car.

Ri-ta cannot shake the image of Ji-sang as a vampire, and his words shock her further. More Ward 21A patients develop abnormal symptoms.

Ri-ta learns that Ji-sang is the boy who saved her as a child. Ji-sang discovers a connection between Jae-wook and his parents.

Ji-sang and Ri-ta share secrets. Ji-sang learns that one of his patients was transferred to Ward 21A. Jae-wook reveals an unexpected plan.

Ji-sang and Hyun-woo vow to stop Jae-wook. Ri-ta begins her own research to help Ji-sang. Hyun-woo examines the remains of a patient from Ward 21A.

Ji-sang and Hyun-woo learn how VBT-01 was created from the journal of Ji-tae’s father, Dr. Jung. Ri-ta finds signs of an intruder in her home.

The condition of Ri-ta’s benefactor takes a sudden turn. Ji-sang tells a grieving Ri-ta that he can prolong her benefactor’s life with his blood.

Ri-ta’s attacker is connected to Ji-sang’s mother's killer. Ji-sang confesses all his secrets to Ri-ta and lets her stay at his home for her safety.

Ji-tae continues his research despite being threatened. Ji-sang saves him from an attack. Ji-sang shows Jae-wook a photo and demands an explanation.