Forensic psychologist Jo McCready is assisting DCI Callum Ferguson on a murder inquiry, when one of her patients is found brutally murdered. Jo was the last person to see Martha Scott alive. She was helping Martha unlock a repressed memory - but during the session, Jo unlocked more than she bargained for. An alternate personality introduced himself as the reincarnation of Jack the Ripper - and thanked Jo for setting him free to kill again. As Ferguson's team race to find Martha's killer, a series of copycat killings begin, replicating 'The Autumn of Terror' in 1888. But if Jack is just a figment of Martha's damaged mind, who killed her? As the body count rises, Jo must construct a profile to stop the murderer recreating the terror of the most infamous serial killer of all time. But not everyone is on Jo's side.