Due to the release of a new product, Seo Jaewon stays in the office by herself till late at night when her longtime stalker barges into the office, trying to attack her. Later, Jaewon finds out the stalker’s identity. Nam Taejoo, an insurance investigator, tells Jaewon that they’re suspecting Jaewon’s stepfather of her mother’s death. Meanwhile, Jaewon sees a suspicious message on her husband’s phone, only to find out later that he is cheating on her.