Child clinician Catherine Dean (Jennifer Lopez) works for a medical research institute that studies the brain. Her mission is to use high-tech means to enter the dreams of young patients and heal the scars in their young hearts. The police received a report that many young girls were missing in the area. The FBI agent in charge of the case (Vince Vaughn) concluded that this was the work of a serial killer. After investigation, the police locked in the suspect, Carl Stagg (Vincent D'Onofrio), but he was tight-lipped and could not rescue the girl he imprisoned. At this time, the police contacted Catherine, hoping that she could sneak into the prisoner's brain through dreams and find the victim's location. However, things are far more dangerous than imagined...