JACK'S BACK

In Los Angeles, a young doctor named John Wesford becomes a suspect when a series of Jack the Ripper copycat killings is committed. John and another young doctor, Jack Pendler, are at the scene of the latest crime in the series; they know each other because they both work for the same medical unit, reporting to the abusive Dr. Sidney Tannerson. Pendler seems to realize that John's testimony will likely lead to his being arrested as the killer and murders him, staging the scene to resemble a suicide. The police quickly name John as the copycat killer and hypothesize that he killed himself out of guilt.

To the surprise of everybody involved, John's identical twin brother, Rick, appears and claims to know John did not kill himself because he has seen visions of the true killer and Pendler killing John. The police humor Rick, but only because his existence calls into question the eyewitness testimony that had put the identical looking John at the scene of the crime, and Rick's suspicious knowledge of the crime scene makes him an attractive suspect himself. Under scrutiny by the police, Rick allies himself with another of John's colleagues, Dr. Chris Moscari, and carries out his own investigation. He successfully identifies, tracks down and confronts Pendler, who attacks him and is arrested. Pendler is in some regards an excellent suspect — physical evidence puts him at the scene of the final murder. But in other regards he is a terrible one, not matching known characteristics or habits of the killer.

Rick continues to dream about John's murder and asks police psychologist Dr. Carlos Battera to hypnotize him to clarify these visions. In the refined vision, he again sees Pendler attack John, but also notices that Pendler's shoes do not match those worn by the copycat killer and that Tannerson had been at the scene. He intuits that Tannerson will next attack Chris and speeds to her house, attracting a string of police cars with his reckless driving. Chris survives and Rick avenges John's death by killing Tannerson, who seemingly had manipulated Pendler into killing John.

Rick discovers that Dr. Sidney Tannerson is the mastermind behind the killings. He confronts and kills Tannerson, avenging his brother John's death and saving Dr. Chris Moscari.

The ending reveals that the true danger lay not only in the obvious suspect but in the manipulative authority figure within the medical unit. Rick's psychic connection to his brother, aided by hypnosis, becomes instrumental in solving the case. The resolution ties together the film’s twin telepathy motif and medical thriller elements, underscoring the dangers of misplaced trust and hidden malice in positions of power.