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.
Faced with the repercussions of their public disagreement, Luther orders Ripley to investigate the Jared Cass murder on his own. Meanwhile, he throws himself into a mountain of cold case files, determined to connect the past and present in order to predict the fetishist's next move.
In a care home, a cancer-ridden patient, William Carney, eagerly awaits a visitor. It is the killer, who has a present for him - pictures of his spoils and promises of more to come.
Ripley has to choose whether to turn a blind eye to Luther's unorthodox policing or go on record with his grievances. In turn Gray finds the line between right and wrong is becoming increasingly blurred as Stark's obsession with Luther deepens.
The discovery of an accomplice forces Luther to engage in a nightmarish duel. Can he win this battle of wits in time to prevent the next horror? Elsewhere in London, a trio of girls looks forward to a quiet night in, unaware the killer lurks in the shadows of their home.
|DCI John Luther||Idris Elba|
|DS Justin Ripley||Warren Brown|
|Mary Day||Sienna Guillory|
|DSU George Stark||David O'Hara|
|DCI Erin Gray||Nikki Amuka-Bird|
|DSU Martin Schenk||Dermot Crowley|
|Benny Deadhead||Michael Smiley|
|Paul Ellis||Kevin Fuller|
|Craig Lane||Selva Rasalingam|
|Dani Lane||Sasha Behar|
|William Carney||Ned Dennehy|
|Ken Barnaby||Lucian Msamati|
|Tessa Barnaby||Maria Miles|
|Dr Joy Harris||Lizzie Hopley|
|Executive Producer||Phillippa Giles|