Lim Takhee is a court lady who has remained by the crown prince’s side through sleepless nights since they were children. As time passes, familiarity turns into affection, and the two are now more intimate than ever. That is, until the crown prince meets his new wife. Takhee becomes anxious as she watches the crown prince, who couldn’t sleep without her, treat the crown princess with kindness. What will happen when her anxiety turns into envy, and then obsession?