In the gripping, twisting six-episode run of Luther, writer/series creator Neil Cross has done a remarkable job of having his cake and eating it too, in a creative (in every sense) manner of speaking: satisfying both the formula requirements of the police/investigative procedural but at the same time venturing into the unexpected, particularly by way of the unusually rich characterizations. After setting up an incredibly trying, cliffhanging predicament for DCI John Luther (Idris Elba)--on top of the many other already-running concerns--leading into the finale episode, it would only reasonably follow for this hour to be even more plot-driven than normal, and early indications point to, if not exactly a clean resolution, then something approaching a more traditional sense of closure. But much like his protagonist, Cross chooses to not only not go the expected route but sidestep any sort of easy out; owing to his literary roots, his focus here isn't so much on a tidy completion of the overall story arc than the culmination of the characters and the greater thematic concerns.
Of course, these greater concerns are, as Cross has deftly done in previous episodes, organic extensions of the plot. Coming full circle with the opening of the series, Luther is on the obsessive hunt for the perpetrator of a horrible crime, but now with the added baggage of both his previous mental break and his particular closeness to this case, he himself is being pursued by the authorities as prime suspect--thus revealing and confirming Luther's colleagues' true feelings about him. However eager she was to have Luther's skill and determination back on her team, it's clear that his boss, DCU Rose Teller (Saskia Reeves), never fully (re-)trusted him; one step further is DCI Martin Schenk (Dermot Crowley), who after having kept a watchful eye on Luther's conduct, seems almost giddy at the prospect of having something concrete on which to bust him. On the flip side, the true depths of Luther's partner DS Justin Ripley's (Warren Brown) loyalty and trust come to the fore, and clearly reveals him as being one of the only two people with any clear understanding of his character.
The other person, of course, is Alice Morgan (Ruth Wilson), with whom Luther, with quite literally nowhere else to turn, reluctantly allies himself--thus not only further cementing the yin/yang, two sides of the same coin parallel Cross has drawn from episode 1, but also boiling the series back down to the fundamental conflict in their respective worldviews: the belief in the existence of love (him) or the world's utter indifference (her). It's no spoiler to say that the answer ultimately rules in Luther's favor--after all, his often over-passionate, but never less than pure, love for estranged wife Zoe (Indira Varma) is one of his primary motivations--but in keeping with Cross's own world view as evidenced in this series, the answer carries with it a myriad of realistically complex, sometimes seemingly contradictory, and always painfully true dimensions. There is love as in Ripley's idealistic lawman loyalty to Luther, but then there's the more twisted but not at all dissimilar devotion Alice has for him. Then there's how the awareness of love's existence can be used as a weapon of manipulation; or, more sincerely but often even more damaging, how love can be so strong as to drive one to act on violent, passionate impulse.
And then there is Luther himself, who exemplifies how the truest, most honest belief in love could be the only thing that can elevate a human above savage animals--and by the hour's end, it is he, for all the more questionable and destructive (to others and most especially himself) acts he has committed, who recognizes that compassion and mercy is a valid, maybe even the best, choice in the face of the most trying and horrific circumstances. But in making that boldest and humane of choices, it leaves one vulnerable to misleading perceptions and very reasonable doubt--making the closing song choice of Nina Simone's "Don't Let Me Be Misunderstood" all too apt, not just in terms of DCI John Luther's situation but that of Cross and the series as a whole. The messy outcome of the tense final moments may leave audiences echoing Luther's final line and thus starving for a second series, but should a follow-up not materialize--though I sincerely hope there will be one--Cross and director Stefan Schwartz, despite any viewer frustration at the absence of a television-conventional close, could not have summed up the deeper, more prominent ideas at work in a more effective, satisfying, and fittingly chilling and haunting manner.