While it comes as no surprise that Luther has garnered notoriety and attention for its title character's weekly investigations of lurid, often grisly, crimes, that is merely the sensationalistic surface that leads to and enriches the true substance underneath--that of writer/series creator Neil Cross's more overarching thematic concerns and, most of all, the psychology of his characters. And so it goes with the second part of the second series' first of two installments; with last week's episode serving more of a "re-set the stage" hour, a simple but incredibly telling lingering shot of DCI John Luther's (Idris Elba) face right before the opening titles pretty much announce that it's back to plunging into more perilous internal waters. While the pursuit of masked murderer Cameron Pell (Lee Ingleby) is as urgent as ever it is so beyond merely keeping the mean streets of London that much safer; as one would expect, the key to capturing Cameron lies in Luther's expert investigative acumen, but even with Luther's partner DS Justin Ripley (Warren Brown) in immediate danger, it also, rather ironically, means him casting aside any sense of human attachment.
For someone so often driven by intense passion and emotion as Luther, this is something a lot easier said than done, but it's a major credit to Elba, Cross, and director Sam Miller how this develops so subtly yet rather surely as the hour progresses, not to mention how Cross interweaves this idea of masks and identity into every plot concern as well as bring the more important ideas clearly to the fore. The serial killer plot does offer up its share of suspense and screams as it works to its Case of the (Two) Week(s) resolution, and the quiet dread with which Miller builds to its climax (aided in no small part to Paul Englishby's haunting score) is far more potent than the rather hackneyed walk through shadowy corridors that capped off last week. But this procedural thread fluidly recedes into the background somewhat and a subplot from the previous week, that of young prostitute Jenny Jones (Aimee Ffion-Edwards), gains prominence. Luther's rescue of Jenny leads to a dramatic encounter with her ruthless boss Baba (Pam Ferris), an even scarier figure than Cameron, but it also comes to inform the greater idea introduced last week by psycho-in-residence Alice Morgan (Ruth Wilson): that of breaking away and starting fresh--but also, more importantly, being free to pursue what you want as who you are. When asked by Ripley why he wears a mask, Cameron simply replies, "Wearing a mask makes it easy"--a statement whose veracity is reinforced later, when team leader DCU Martin Schenk grills a perp (in a truly spectacular scene for Schenk's portrayer, Dermot Crowley) and too truthfully declares "It's amazing how our faces betray us."
And, going back to that pre-title shot of Luther, it is clear that while the veneer shows him as ideally on-the-ball as as he's ever been as a cop, it's just that--a mask that, indeed, makes it "easier." While his colleagues commend him--an amusingly far cry from series 1, where for however well he did, there was always that air of unease and distrust--leave it to his twisted kin Alice to effortlessly recognize what is truly going on within Luther. Wilson's screen time this week is once again limited, but once again does she ever make it count; in an hour with Cameron and his mask, Baba and her hammer (figuratively and literally), and one hell of an intimidating monologue by Schenk, it says it all that Luther's encounter with Alice is, as usual, the most tense and unsettling scene of them all, what with the ongoing threat not of physical violence, but of the psychological and emotional sort. That, indeed, does manifest in Alice's ever-creepy yet ever-alluring way with words, but most disturbingly in Luther's cold, uncharacteristically detached (non-)reaction, appearing to have succeeded in completely sacrificing and assimilating his identity into the monolithic mask of duty. But Alice knows best, for not long after they part, Luther commits a generous gesture of kindness--and, while the hour ends with various relationships and circumstances again juggled and redrawn, as Cross has shown us all episodes prior, however much Luther means well for others, it almost assuredly won't mean the same for himself.