A critically injured man receives an experimental brain implant that saves his life. But then he begins to see a series of brutal murders from the killer's perspective. Worse, the killer can see through his eyes, too, and means to find and kill the only witness to his terrible crimes. With time running out, the doctor who made the implant realizes the truth: her patient's implant is communicating with another patient's implant. But can she figure out which other patient?