Jenny Davin (Haenel), a hard-working young Belgian doctor, is wrapping up her days at a small free clinic in Liège, having accepted a new job at a larger practice. She is exhausted after a long day of seeing patients and dealing with her petulant intern, Julien (Bonnaud). When the buzzer rings after hours, Jenny instructs Julien to ignore it. The next day, Jenny is devastated to hear that the person who rang the buzzer the previous night, a young African woman, was found dead by the river, her skull fractured. Surveillance footage shows the young woman running away from someone and banging on the clinic door in desperation. Guilt-ridden, Jenny is determined to find out who the unknown girl was.