When Hye Young (Jang Seo Hee) hears that her daughter Yoo Ri (Kang An Na) has been found dead in a car with two other students, she is understandably distraught. However, Hye Young rejects the police's suspicion of a group suicide, believing that her "model student" daughter would never take her own life, accusing Yoo Ri's idol trainee classmate and homeroom teacher of being involved in her death. As the police and Hye Young's own investigations unfold, conflicting stories begin to emerge, and Hye Young is forced to reckon with the possibility that her overbearing "love" may have driven her daughter to conceal dark secrets.

Seo Hye Young is in her second-year fellowship as an obstetrician-gynecologist who practically lives at the hospital. She's a workaholic and a highly skilled doctor with quick and precise hands. During her relationship with Yoon Seo Jin, she discovers she's pregnant. Despite her desire to stay at her university, she's reassigned to a countryside hospital branch after performing an abortion surgery on a woman carrying her second child with a disorder. There, she encounters Lee Sang Sik, a pediatrician. Their paths cross coincidentally in an elevator, and he becomes the only one aware of her pregnancy. As Hye Young overworks herself, Sang Sik cares for her, and she gradually opens up to him.