Strange events begin when Olivia (Chiara Conti) and her four friends hold a purifying water fast at her secluded cottage. Docile and introverted, Olivia is easy prey for her deceitful guests, who ridicule her and her long-lost twin - an unborn child "absorbed" by Olivia during the childbirth that killed her mother. Tormented, Olivia ferociously removes the only palpable link she has with her dead twin - a tooth lodged beneath the skin of her shoulder. But discarding it down the drain only brings the horrific past to the surface. Just as water awakens this hidden life, it is water that will gruesomely take life away...