Lee Yeong Oh is a brilliant neurosurgeon who returns to Korea after studying abroad. He begins working at Hyunsung Hospital alongside his father, Lee Gun Myung, the respected head of the cardio-cerebrovascular center. Despite his talent, Yeong Oh struggles with an antisocial personality disorder that leaves him unable to empathize with his patients.

One day, traffic police officer Gye Jin Sung witnesses what appears to be a fatal accident—but she suspects it’s actually a murder. She rushes the victim to Hyunsung Hospital, where her crush, cardiothoracic surgeon Hyun Suk Joo, and Yeong Oh perform surgery. When the patient dies, Jin Sung begins to suspect Yeong Oh of wrongdoing.

As more mysterious deaths occur in the hospital, Yeong Oh launches an investigation of his own, uncovering secrets that may link the incidents—and possibly himself—to something far more sinister.