Eve Waller is the family matriarch who moves into the house with the cursed pool. Initially supportive of Ray's hydrotherapy, she soon grows suspicious of his drastic behavioral changes. She actively investigates the property's dark history, uncovering the truth about the ancient entity and its lethal sacrifice demands. Fiercely protective of her children, she battles the possession to save them and ultimately makes the decisive choice to fill in the pool to prevent future tragedies.