Sophie Hartley is a successful illustrator under pressure and terrified of failure. To make matters worse, things aren't going well with her husband Craig. When Sophie becomes convinced that she's being stalked by one of Craig's co-workers, Mara, no one believes her. Sophie's life begins to fall apart. She feels she's being watched, followed, copied, it is clear to her that Mara is trying to steal her husband, her daughters, her life. Forced to prove her sanity, Sophie grows increasingly paranoid - is she imagining things? She becomes completely caught up in her obsession, turning stalker herself. Sophie spirals further out of control and as a result of her own dangerous actions, loses both Craig and custody of her children. With the loss of all she holds dear, Sophie begins to fight back. But before she regains her family, she discovers something more frightening than anything she has ever encountered. A secret that can paradoxically destroy or heal...