Sydney Wells (Jessica Alba) is an accomplished concert violinist who has been blind since a childhood tragedy. Sydney undergoes a double corneal transplant, and her sight is restored. But Sydney's happiness is short-lived as unexplainable shadowy and frightening images start to haunt her. Are they a passing aftermath of her surgery, Sydney's mind adjusting to sight, a product of her imagination, or something horrifyingly real? As Sydney's family and friends begin to doubt her sanity, Sydney is soon convinced that her anonymous eye donor has somehow opened the door to a terrifying world only she can.