After their mother's tragic and untimely death several years ago, the siblings Niklas and Lisa have been struggling to piece their lives back together. While Lisa chose to run away and find a new life elsewhere, Niklas has stayed behind to take care of their grieving father. When the horrific and seemingly supernatural death of his classmate coincides with the return of his long-lost sister, the high-school student's fragile sanity is quickly falling apart. As terror spreads among the students, Niklas is forced to deal with adolescent drama, mental illness and the rising suspicion of being a killer. At the same time, Lisa starts to have strange visions of her mother, blood rituals and the occult. As she digs deeper into her mother's mysterious death, an evil from the past reveals itself to feast on the chaos and misery of humankind...