During the day and in the middle of downtown, Soo-A (Gang Ye-Won) is taken away against her will and brought to a psychiatric hospital. She is locked up there without knowing why. She is constantly injected with drugs and undergoes cruel violence. Soo-A begins to write down in detail all of the horrific acts that take place at the psychiatric hospital.
One year later, a notebook is delivered to Nam-Soo (Lee Sang-Yoon). He works as a PD for a broadcasting station. Nam-Soo reads the notebook and feels horrified by what happened. To uncover the truth, Nam-Soo seeks out SooA. She is now in prison as a murder suspect.