Min-ji is an ordinary housewife with a dark secret. Unlike the wishes of her husband, In-gyu, who has a business running resorts, they don't have a child yet. They've tried test tubes and home remedies, but nothing has worked. Her husband and her in-laws finally decide to get a surrogate mother, and Min-ji has no choice but to agree to it, as she is worn out from their pressure. Hometown friend Jeong-ah comes knocking on the door. Min-ji is uneasy with Jeong-ah around, as she knows her past secrets, including the time she lived with someone else and had an abortion. On the other hand, In-gyu has completely fallen for bold and sexy Jeong-ah. Like a crow that nests in another's nest, Jeong-ah takes over Min-ji's place slowly and gradually. Min-ji is driven into a corner, so she meets Jeong-ah's husband, Joo-sik, to stop her. However, she falls for his trap and is used to replace his wife who ran away from home.