Seo-Rin (Lee Yoo-Young) works as a high school teacher. Her life is going and she is about to get married soon. One day, she drinks coffee at her desk and falls asleep. The next day, she receives a text message that asks "Did you have a good dream?" and a photo is on her phone. The photo shows Seo-Rin partially undressed. Seo-Rin and ex-detective Kook-Cheol (Kim Hee-Won) work to find out who is responsible.