A year after the death of estranged wife Zoe and best friend Ian Reed's betrayal, Luther remains tortured by the past, as the drama starring Idris 'The Wire' Elba as the near-genius murder detective returns. While Alice bides her time in a psychiatric unit and Ripley languishes in uniform, Luther has been shut away with dusty files working on cold cases. His only solace exists in his newfound friendship with Mark North and their late-night chess games - forever bonded by the person that once divided them: Zoe. Former investigating officer Martin Schenk offers Luther a role in the new Serious and Serial Unit, and Luther accepts. He is determined to devote his energy to reinstating DS Justin Ripley as a rising star in the police force and help those who he inadvertently hurt or compromised in the past, including Alice.