For Luther (Idris Elba), his profession is a vacation rather than a job. He serves his own idea of a moral order as much as the rules and codes of criminal law. John Luther is a deeply troubled man, a philosophical cop possessed by the insoluble problem of evil and justice in a Godless world. Confronting depravity in its many terrible forms, over a succession of psychological duels between hunter and hunted, perpetrator and prey, Luther reveals his capacity for violence as well as kindness; his sudden vulnerability and dizzying, visionary mind; why his wife left him for another man and why his colleagues are frequently left open-mouthed in awe.
However, as the intensity of his convictions combine with the violence of his passions, they provoke the question of whether Luther is a force for good or a man hell bent on self-destruction. Luthers confidante is his arch-enemy Alice, a beautiful multiple-murderess who evades his grasp early on and with whom he becomes locked in a lethal battle of wits.
As the stakes get even higher and more personal, Luthers lonely path pulls him towards the very edge of temptation. Will his personal demons prove to be as dangerous as any of the criminals he pursues?