Twenty years ago, 8-year-old Emma Brody's abusive mother smashed Emma's face into a bathroom mirror just for pilfering in the mother's makeup drawer. Today, Emma is an independent, self-assured woman who plays violin in a popular Celtic folk band in Chicago. Emma lives life on her own terms, only without sight -- the result of the traumatic injuries to her eyes at the hands of her mother. Luckily for Emma, medical science has vaulted a quantum leap in the past two decades. Now, thanks to corneal implants installed by her kindly eye surgeon, Dr. Ryan Pierce, Emma can see again. Emma's sight is at first cloudy, and she suffers from "retroactive hallucinations," a clinically documented syndrome in which the newly sighted sometimes "see" things hours, or even days, after they actually happen. This becomes a big problem when Emma sees a suspicious man leaving her neighbor's apartment at 4AM, but his features appear to her only in flashback later that morning. After failing to get a response at the neighbor's door, Emma tries to convince detective John Hallstrom and his partner Tom Ridgely to check things out. At first, Hallstrom dismisses Emma as a nutcase, but when the cops finally arrive on the scene, they find the guy murdered, using the same MO as a series of killings that Hallstrom and Ridgely are already investigating. Emma herself is in danger, because she's the only person who can identify the killer. Hallstrom's colleagues remain doubtful because Emma's vision flawed. When the killer begins to stalk Emma, Hallstrom has her placed under police protection, and the two soon become lovers while Hallstrom tries to figure out who the killer is.