Joo-yeon marries into Horizon family. Daughter Su-hyeon reported dead; family reactions strange. Joo-yeon finds hidden records. She meets detective Chang-ho, who suspects Horizon and collaborates. Housekeeper Mi-seon learns her child Jung-hyo was disposed of and testifies. They unite to uncover Horizon family's illegal infant experiments and biological trafficking. Joo-yeon rescues Su-hyeon from the hospital basement. Mi-seon dies. Chang-ho stays with Joo-yeon. Truth revealed.