Dr. Helen Hudson, a criminal psychologist and expert on serial killers, becomes agoraphobic after a traumatic encounter with a killer she had been profiling. Confined to her apartment, she communicates through the internet and phone. When a series of murders occur in San Francisco, detectives M.J. Monahan and Reuben Goetz seek her expertise. The killer seems to be imitating infamous serial killers from the past, using their methods to commit his crimes. Hudson, despite her debilitating condition, is drawn into the investigation, offering insights from her deep knowledge of serial killers. As she delves deeper into the case, she realizes that the killer is obsessed with her work and is attempting to communicate through his crimes.

The investigation becomes increasingly intense, with Monahan and Goetz facing mounting pressure to catch the killer before he strikes again. Hudson’s involvement puts a strain on her already fragile mental state, but her insights prove invaluable. The detectives must navigate through a web of clues and psychological twists, racing against time to prevent more murders. Meanwhile, Hudson is forced to confront her own fears and the lingering trauma from her past, which may hold the key to understanding the killer's motivations. The case pushes everyone to their limits, leading to a tense and climactic confrontation as they get closer to identifying the copycat killer.