Han Yi Han was a outstanding surgeon. He specialized in two departments: general surgery and cardiothoracic surgery after graduating from the leading medical school in South Korea. One operation transformed his life. Han Yi Han believes he performed a successful operation, but the patient died. His medical license was then revoked. Four years later, Han Yi Han specializes in medical disputes as a lawyer. He also attempts to discover the truth about his former patient's demise. Han Yi Han attempts to penalize individuals who commit medical malpractice and carelessness during his trials. He works with a prosecutor who lost a family member and a lover as a result of the surgery conducted by Han Yi Han.