Prior to becoming a doctor, Yoo Hye Jung was a rebellious teen, always ready for a fight. She meets Hong Ji Hong, a teacher at her new school, and the two immediately butt heads.
Hye Jung is inspired to turn her life around after witnessing Ji Hong's medical expertise. With midterms approaching quickly, she must find a tutor to help her study.
Hye Jung takes on more blame than she should after the abandoned building fire. Ji Hong is met with consequences of his own regarding the photo scandal.
Back in the present day, Hye Jung is a neurosurgeon starting her first day at Gookil hospital, where she quickly runs into a few familiar faces. However, not everyone is happy with her presence.
Adamantly seeking revenge, Hye Jung takes new steps to unveil the truth behind her grandmother's death. A loved one's health scare puts Ji Hong in a fragile state.
In the series finale, Director Jin must undergo risky surgery at the hands of Ji Hong, who wants Hye Jung to assist. But will she agree to save the person she's sought to destroy for 13 years?