Passionate, committed and just on the right side of ruthless, John Luther is back stalking the streets of London searching for the evil that lurks among the city's many dark streets and doorways.
This season sees a twisted fetishist targeting young women in the capital. The killer has struck once already and Luther is convinced he's going to kill again and again, until he is caught.
But with London's best detective ordered to investigate another case – the murder of an internet tormentor – the chances of catching him before he strikes again are shrinking.
A heavy work load is not Luther's only problem. His life is made doubly complicated when it emerges that his worst enemies are his own colleagues, and they're willing to break every rule in the book to bring him down... including targeting trusted colleague Ripley.
As cracks splinter the foundations of Luther and Ripley's alliance, will Ripley turn a blind eye to Luther's antics or will he go on record?
After years of grief, a chance encounter means that this lonely detective might just be on the verge of finding love. But is Mary Day ready to accept Luther's past? And can Luther leave it behind?
When a vigilante killer embarks on a crusade to punish criminals, Luther is forced to confront his own sense of morality. Can he walk the line between right and wrong and do his job or has he finally met his match? Pressure increases from all sides, pushing Luther to his limits – threatening everything which he holds dear.
Crackling with energy, beautifully shot and packed with tension from the very start, this season sees Luther take a twisted journey as he solves some of the darkest crimes of his career.
Season 3 premiered on BBC Entertainment on Sunday 29 December 2013, at 20h30. New episodes broadcast in a double bill on consecutive nights (29/30 December).