Oh Mal-Soon (Nah Moon-hee) is a 74-year-old widow that realizes she is becoming a burden on her family. As she is roaming the streets, she comes across a photo studio and decides to dress up for a self- portrait. When she walks out of the photo studio, she mysteriously turns back into her twenty year old self. Making the most out of this one in a lifetime opportunity, she changes her name to Oh Doo-Ri (Sim Eun-kyeong) and decides to make the most out of her youth.

Based on actual events that took place at Gwangju Inhwa School for the hearing-impaired, where young deaf students were the victims of repeated sexual assaults by faculty members over a period of five years in the early 2000s.

In 1636, the Qing dynasty attacks Joseon. King Injo and his retainers, including Choi Myung-kil and Kim Sang-hun, hide in the mountain fortress city of Namhansanseong. They are isolated from the outside. Meanwhile, Choi Myung-kil insists that they enter into negotiations with the Qing dynasty, but Kim Sang-hun proposes that they keep fighting.