Joohyun can't escape the nightmares of her past, working in the facility occupied by horrible misery and despair she struggles to end each day. Loneliness and insomnia take tool on her mental health - her empty studio and fascination with velvet notebooks don't bring her happiness anymore. One day, she is assigned to a new case in the governmental area of the facility she work in. The news of 8 cases crash upon her as she is to be the nurse for the case number 04. In the chaos of the new position and danger she finds that 04 is a man that will leave her heart either broken or mended.