Song Yeo-Wool (Cho Yeo-jeong, in her first major dramatic role since Oscar-winning movie Parasite) was a lawyer who had it all: A high-flying career, a wealthy and loving husband, and a precocious young son. But her world turned upside down a year ago when she was falsely accused of murdering her husband in a mysterious yacht accident. The case remained unsolved and she continues to cope with the loss of her husband. In the present, Yeo-wool gets an exclusive invitation to enroll her son in a prestigious prep school in Jeju island. She sees it as an opportunity to get away from her tragic past and focus on spending time with her son. So she quits her job and moves to the beautiful island where her late husband already has an estate ready for her. However, her son’s new school is controlled by a tight circle of snobbish mothers who ostracise Yeo-wool for being a ‘murderer’. Then one of the other mothers from the school offers her support, and Yeo-wool’s fortunes look to be lifting, but all is not as it seem—it turns out, the invitation to the school was not pure coincidence but part of a larger scheme.