Soo Young, a police detective who went to prison for someone else, is surprised when a mysterious woman named Yoon Sun arrives to collect her on her day of release. As she discovers that the promised compensation for her time behind bars has vanished, Soo Young embarks on a mission to reclaim what rightfully belongs to her. Soo Young uncovers that the man behind it all is Andy and embarks on a relentless pursuit. Fueled by her unwavering belief that "promises must be kept", Soo Young charges toward her singular goal...