She, a girl brought back from the orphanage by the organization, had to undergo many tests with him since she was a child, risking death to work for the organization. Now, she is tired of the life of fighting and killing, and is determined to leave this ruthless place to find an ordinary life. He is willing to pave the way for her. However, she eventually discovered that she had an inseparable relationship with the organization, and her life experience was hidden under a layer of mystery. For him and to find the truth about her life experience, she returned to that suffocating place...