Ja-yoon is a high school student who struggles with memory loss after she endured some unknown trauma during her childhood. While trying to uncover the truth, she is unwittingly dragged into a world of crime and finds herself on a journey that will awaken many secrets hidden deep within.
Amid a coup, a North Korean agent escapes south with the country's injured leader in an attempt to keep him alive and prevent a Korean war.
Jung-yeon receives a tip-off that her son who went missing six years ago is in a fishing village. Local officers get in her way, trying to cover up a secret that might be related to her case.
Ji-woo, an outcast at a prestigious private school, meets Hak-sung, the school janitor who is actually a mathematical genius who defected from North Korea.