A woman becomes dangerously obsessed with her ex-husband after he moves on and becomes engaged to someone new, going to increasingly disturbing lengths to destroy the new relationship and reclaim what she believes is hers. As the new fiancée begins to suspect that something sinister is unfolding, she struggles to convince those around her of the threat she faces. The film builds into a psychological thriller centred on jealousy, manipulation, and the lengths to which a scorned person will go.