Luther investigates a the case of a fetishist who is murdering women which is similar to an unsolved case from the 1980s. The team attempt to catch the copycat killer, whose murderous spree has only just started.

Luther's date with Mary, and the promise of romance, is interrupted by the news of another murder. The killer has struck again - the number of victims is escalating fast.

Away from the police force, Luther receives a visit from Detective Chief Inspector Theo Bloom and Detective Sergeant Emma Lane. They bring him some new evidence that will draw him back to London to find the truth. The team tracks a cannibalistic serial killer.

On the trail of a horrifying killer, Luther finds himself haunted by ghosts from his past.