At 2 a.m., an innocent woman's scream for help was heard. Sang-hoon (Lee Sung-min) witnessed the murder on the balcony. When he was about to call the police, he unexpectedly made eye contact with the murderer, making him and his family the next target of the murderer. In order to protect himself and his family, Sang-hoon had to hide the fact that he saw the murderer from the police, and began a thrilling pursuit with the murderer...