This review contains plot spoilers and is based on the UK preview of the episode.
 

This review contains plot spoilers and is based on the UK preview of the episode.

'The Reichenbach Fall' borrows several things from 'The Final Problem', a short story known not only for its showdown between Holmes and Moriarty, but also for its author's attempt to kill off his most famous of characters. This episode elaborates on the expected confrontation between consulting detective and consulting criminal, but it also incorporates the story-about-the-story by making authorship – and the power of storytelling – one of its major themes. The clash between Doyle-as-author and Holmes-as-character has been played with before, particularly in Gilbert Adair's (2009) novel inversion And Then There Was No One, set at a Sherlock Holmes Festival near the Reichenbach Falls, and in which a detective character kills off their author. Less insistently postmodern, Steve Thompson nevertheless weaves the concept of a tension between storyteller and story firmly into his hero-villain face-off. Like Adair he also opts for a radical inversion: Sherlock is seemingly re-narrated and repositioned as the black-hat, the baddie of the piece. Holmes' “fall” is literal and metaphorical at the same time – a fall in status from hero to very nearly zero.

Making this episode an epic struggle over who gets to be the hero and who the arch-nemesis, who the author and who the character, who ordinary and who extraordinary, is a wonderfully post-Unbreakable idea that is generally well executed by Steve Thompson. At times, this is almost Sherlock-meets-Shyamalan by way of Philip K. Dick-style reality-bending. There are occasional plot holes amongst the meta-plotting, mind you: Moriarty's identity as “the Storyteller” from kids' TV – “it's on DVD”, he offers as a clincher of reality – would presumably have been easy enough for a journalist to verify, but thorough fact-checking evidently isn't something done by faux fan Kitty Riley (Katherine Parkinson). And Moriarty's decision that the only way to foil Sherlock is through self-sacrifice doesn't ring true, even if it tidies away story strands and makes Holmes' fate all the more inevitable.

There's something else that doesn't ring true. If a TV production is going to rely on many newspaper headlines flashed up momentarily and stylishly on screen, then it strikes me as mildly important that these headlines should be spelled correctly – so how can a prestigious series get to air with “Scotland Yard embarrased by overlooked clues” in one headline, and “Scotland Yard calls upon 'nation's favourite detective' in Moriarty trail” rather than trial in another? Journalists don't check facts anymore, and nobody checks their spellings – I''m not sure this is what's meant by a “Sherlock for the twenty-first century”. In a story that's otherwise so immersive, even split-second typos can intrude on the illusionism.

And though what eventually unfolds is a grim fairytale, it's made more believable by the return of police characters from 'A Study in Pink', a masterful stroke which lends weight to the feeling that the series itself is being book-ended and brought full circle towards genuine closure. Thompson also craftily exploits both the audience's and Sherlock's belief in Moriarty as a criminal mastermind: we're convinced by the missing computer code, and by Moriarty's opening apps for law-breaking, precisely because this type of story requires its villains to possess exaggerated, impossible, near-magical powers. We, all of us, even Mycroft and the British Establishment, fall for Moriarty's publicity and celebrity. No wonder he loves newspaper fairytales.

Director Toby Haynes is known for his use of tone-setting music on-set, and this episode makes repeated use of pre-existent (rather than specially scored) music on its soundtrack, making me wonder whether these pieces were included as temp music tracks and simply left in place as the best possible option. The homage to A Clockwork Orange as Moriarty smashes his way in to the Crown Jewels is one highlight, and Haynes' direction holds its own in comparison with Paul McGuigan's work on the previous two episodes. The ultimate meeting between Sherlock and Moriarty is also sharply directed and well played out, teasingly reusing "Stayin' Alive", and Haynes' decision to directly show Sherlock's fall rather than leaving it off-screen is another outstanding choice. Unlike 'The Final Problem' where Watson has to imagine Holmes' demise in his mind's eye, here neither John nor the audience are spared the sight of Sherlock's billowing-coated plummeting toward the London pavement. It makes this sequence almost painfully visceral, and punches home the fact that there can be no way out for Sherlock, no clever last-minute escape. Like all the best magic tricks, here it plainly is; we've seen it happen with our very own eyes. "Keep your eyes fixed on me", Sherlock tells his witness.

Just as I thought the CGI hound last week was a misjudgement, I wasn't wholly persuaded by the very last shot and its final resolution of the “final problem”. Leaving viewers speculating “how did he do that?” seems, to me, far less powerful than leaving the question “did he do it?” hanging in the air. At the very last gasp, then, 'The Reichenbach Fall' pulls its punches, not wanting to provoke audiences too powerfully. I'd argue that this episode would have been a braver, bolder piece of TV drama – and an even stronger piece of storytelling – if it had ended with John Watson speaking to Holmes' gravestone rather than on that panning shot.
What we are left with is a story that has to be re-told and re-inflected by its audience in order to fully make sense, with new bits of explanation being needed to iron out How It Was Done. “It's a trick, just a magic trick”, Sherlock says to John of his deductive powers, whilst also confessing under duress to be a “fake”. The trick, and the fakery, are both perfectly true – but Thompson's script is pure Moffatesque misdirection here, because they don't refer to what we might assume. "SUICIDE OF FAKE GENIUS" announces The Sun, except this made-up headline contains all the right words, all spelled correctly, just not in the right order. And perhaps this is Steve Thompson's cleverest trick of all – that in an epic, twisting story about storytelling, concerning who has the power and the agency to construct heroes and villains, it isn't the storyteller or the author who wins. This time it's the character who's triumphant, though can it ever really be anything else where Sherlock Holmes is concerned? The result is that fan audiences are ultimately given the power, for now, to invent their own final resolutions to this particular problem (even if Sherlock's taxonomy of fandom is more than a little retrograde). Moriarty, or Richard Brook, can't tell Sherlock's story... but the somewhat open ending leaves audiences and fans to do just that. Television has all the best tricks.

Far from indicating a fall from grace, series two has been a wonderful, palpable high for the Sherlock production team. Both in front of and behind the camera, this is TV drama hailing from “the best and the wisest”, to appropriate a few of Doyle's final words from 'The Final Problem'. Hopefully Sherlock's resurrection won't be too far off, and we'll be back with "CSI: Baker Street" before long.

This review contains plot spoilers and is based on the UK preview of the episode.

Boasting an extremely sharp script by Mark Gatiss, this is a textbook modernisation of an iconic Holmes tale, one which seizes hold of its best-known images (fogbanks twisting upon the moor; a howling, mysterious hound) and twists them into radical new narrative shapes. Where last week's episode faltered via its transformation of Irene Adler – a strong, intelligent woman reimagined as a damsel in distress undone by her emotions – this week's updating hardly puts a foot wrong. It constantly plays with audience expectations, shuffling narrative roles between characters who largely carry the same or similar names as those in the original story. The naturalist Stapleton is converted into a gene-manipulating scientist Dr Stapleton (Amelia Bullmore), immediately raising the question as to whether she will be the villain of the piece. And eccentric Frankland is also rendered as a Doctor (Clive Mantle), being given some of the narrative business displayed by Stapleton in the original when he recognises Holmes and Watson and professes to follow their exploits. This version of Frankland is introduced as something of a fanboy, poring over John's blog and joking about not recognising Sherlock without his hat. But in the end, it seems that fandom doesn't pay.

As events unfold, Gatiss's take on 'The Hound of the Baskervilles' reveals its transformative contours. This time round there's no Baskerville family, meaning that Sir Henry needs a new surname and so punningly becomes Henry Knight, portrayed effectively by Russell Tovey. This isn't the last of Gatiss's puns, though, since his work here is dominated by word play.

Signalling on the moor, for instance, is given a new and unexpected twenty-first century explanation. And though the term itself is never used (presumably in the interests of not falling foul of the BBC's watershed), audiences are nevertheless left to join the dots and complete the gag: Watson has uncovered an instance of moorland “dogging”. This playful use of language is, in fact, curiously in keeping with the spirit of the original story, since Conan Doyle has Holmes describe Sir Henry as “being dogged [i.e. pursued] in London”, while Watson later reiterates “it is he who dogged us in London?”. Whether via “dogged” pursuit, or “dogging” as a pursuit, appropriately doggy language playfully proliferates in both the original and Gatiss's reworking.

Keeping phrases from a 1901/2 tale relevant in the twenty-first century is a further problem that Gatiss confronts head-on. As such, the act of adaptation becomes part of the narrative itself, with Henry's use of the word “hound” becoming a key component in the mystery that attracts Holmes' attention. Henry is even made to “repeat exactly” his phrase, “they were the footprints of a gigantic hound”, emphasising that Gatiss is exactly repeating Arthur Conan Doyle, with Henry's “archaic” language becoming a puzzle in need of explanation rather than mere fidelity to the original. In essence, Gatiss makes the very problem of modernisation – how can a menacing “hound” be seriously spoken of in the present day? – a mystery and a question of the case itself.

Even the iconic visuals of previous film and TV incarnations of 'The Hound of the Baskervilles' are played with and given a new narrative focus. The fogbanks that roll in imposingly at the original story's denouement, becoming almost another character in the final resolution, are given a fresh starring role. Like the hound, overly familiar images of dangerous moorland mist are made new by being brought into the narrative's structure in an unusual way. Both familiar language (the hound) and foggy imagery are hence drawn directly into the back-story of the “brilliant” case that Sherlock has to solve. Gatiss's solution to updating 'The Hound of the Baskervilles' thus has an elegance and a satisfying coherence. Even Sherlock's deception of John, revealed in a closing twist, relocates a deception played by Holmes in the original, again feeling true to the spirit of the tale.

Revelling in the visual style that he has pioneered for the show, director Paul McGuigan clearly enjoys several sequences in particular: the flow of information regarding Sherlock's infiltration of the Baskerville military installation is extremely well incorporated into his movements through the place, heightening tension in this entire sequence. And Sherlock's “mind palace”, as he explores all possible meanings of “Liberty In” is also uber-stylishly depicted, adding to the sense of Baskerville's labs as a techno-fetish akin to the rebooted bridge of the starship Enterprise, all gleaming white and excessive lens flare. For a moment or two, it seems as if Benedict Cumberbatch has already wandered onto the Star Trek set.

Viewed in isolation, the narrative trick played with Bluebell the luminous bunny would be a good one: what seems like a comedy case to be dismissed by Holmes ends up being crucially related to the matter at hand. But this is the exact same sleight-of-hand utilised in Moffat's script last week, meaning that as a device it instead becomes a touch clunky and repetitive here. A strong-willed script editor would, I think, have given some pointed notes on this unintended repetition, but since both scripts are from the show's co-creators then perhaps they were (literally) left to their own devices. Fingers crossed that Steve Thompson doesn't do the same thing again next time and try for a hat trick of 'background cases that end up being foreground cases'.

If this episode does perhaps put one other foot wrong, then for me this lies is in its eventual depiction of the terrifying hound. Glimpsed as a CGI creation, the red-eyed canine ends up as a proficient but nonetheless rather generic SFX depiction – it looks just how you'd imagine it would in a contemporary TV drama worked on by The Mill. As an audience, we therefore see exactly what we expect to see, rather than something truly threatening or out of the ordinary. Instead of giving into conventional thinking that special effects wizardry should cap the narrative, I think this particular hound would have been far more effective if it had been left off-screen altogether, never clearly seen by viewers. Left to imagine what had so terrorised Henry, John and even Sherlock himself, this tale could have possessed far more lingering power. It is, after all, a visual logic of absence and implication that marks most of the rest of the story's direction and editing with regards to the hound; the shiny CGI version seems out of place with the majority of Paul McGuigan and Charlie Phillips' work in this case, as well as with the episode's outstanding use of sound design.

Leaving aside this arguable misstep, we do get to see something genuinely unexpected: Sherlock's faith in reason and detachment are threatened, if only temporarily, when he sees the shaggy dog at the heart of the story. Benedict Cumberbatch relishes the chance to explore a more unhinged Holmes, and this is a striking scene showing that there may be further new territory for Sherlock to mine in future.

Losing Grimpen Mire as a feature means that the episode necessarily evades getting bogged down in a standard ending, but the presence of a Grimpen Minefield is instead clearly telegraphed to viewers. And so once the villain is unmasked then the storyline's development is fairly transparent. But even this most predictable of plot beats is well executed, and substituting a big explosion for a muddy demise does at least have the virtue of being more visually spectacular as well as more televisually convincing (perhaps it's just me, but filmed versions of death-by-marshland tend to look very hackneyed, if not mildly absurd).

Exceptionally clever from start to finish, this episode pretty much outdoes 'A Scandal in Belgravia' as an updating. I may have enjoyed last week's cut-and-thrust a little more overall, but this is by far the more inventive, coherent piece of Holmesian modernisation. Mark my words, you'll never think of mist-wreathed moors or the “hound” in quite the same way again, given acronymic thrills in Sherlock's storytelling.

This review contains plot spoilers and is based on the UK preview of the episode.

If there isn't already a website or blog called 'The Geek Interpreter' then I expect there'll be one along asap. Any takers? May be I should just set the thing up myself. Because this is an episode of Sherlock which revels in playfulness – playing with the Internet reception and 'geek interpretation' of the first series (Sherlock himself is an online “phenomenon”); playing with fan readings of Sherlock and John as a couple (or not); and playing with the plot beats of 'A Scandal in Bohemia'. I'd argue that it's Steven Moffat's freshest and most joyous writing for quite some time. Where his 2011 Doctor Who Christmas Special felt like it was written to fit an increasingly rigid formula, here the reverse seems true: rather than feeling forced into a TV industry template, this is a free-wheeling development of Arthur Conan Doyle's work which delights in putting new spins on Holmesian lore. 'The Geek Interpreter' is just one of the many glorious shots fired across the Canon, and the fact that it's always 1895 on the visitor count of John's blog is another stand-out moment. Some references appear to be more Doctor Who-oriented rather than Sherlocked. “No. I said, no”... “when I say run, run”... surely these are in-jokes cast in the direction of Doctor Who fans in the audience.

And then there's the infamous headwear. Moffat frequently enjoys some hat-related business in his scripts these days, almost as much as he seems to draw on phone-focused shenanigans – a motif which is there right from the beginnings of Press Gang, through into Coupling and even Jekyll. Indeed, 'A Scandal in Belgravia' offers up some fine opportunities for characteristic Moffatisms – for example, the phone call (or here, the text alert) that opposes expectations by revealing its receiver's immediate proximity. It's a device used at least twice in this script alone. If a trick's worth playing, mind you, then it's surely worth re-playing.

There's a danger, I suppose, that this series two opener might feel like a mere replay or retread of series one's successes. It doesn't. From the astounding cliffhanger resolution onwards, there's a sense of Moffat and the entire team going all-out to top both 'The Great Game' and series one in sum total. The absurdist get-out to series one's cliffhanger is instantly destined to become a classic TV moment, playing against the established tone of intense drama, and encapsulating that most contemporary of experiences – the mobile that goes off with radically inopportune timing (not to mention the choice of ringtone that suddenly betrays its owner).

A very few ideas struck me as problematic – would Irene Adler's nakedness really render her impervious or cloaked to Sherlock's deductions??????? (Surely there are just as many clues to be read from an undressed body as a dressed one?). And elsewhere, how convincing was it that that boomerang could impact with sufficient force to kill a man, before then rebounding some distance into the water? The hiker puzzle required it, but this set-up felt a touch strained and ersatz, even for a B-plot or C-plot distraction.

There are many key changes in relation to the original tale (beyond the whole conceit of the series, obviously). For one thing, “the woman” is now Adler's professional title rather than Sherlock's own personal moniker for her – and although Cumberbatch is given dialogue where he stresses and savours and individuates the definite article, I can't help but feel that a dimension of Holmesian meaning is lost here, even while “the woman” emphasises Adler's status as dominatrix, and the power struggles she engages in. More successfully, it is our own royal family who are implicated rather than an obscure European lineage, a shift that helps bring home Adler's initial threat rather than it seeming more remote. (Moffat also thankfully avoids a certain ludicrousness encountered in the Jeremy Brett version, where a slightly wooden King arrives looking like a rejected 1960's Batman villain). The major concluding incident in the written tale – Irene being tricked into giving up her photograph's location – is repositioned early on in this riffing on the short story, along with Watson being given a far stronger, punchier role in the subterfuge that's needed to gain access to Adler's residence.

Most significantly of all, though, it is Sherlock who ends up triumphant rather than Irene – while she definitively bests him in the short story, here it is Holmes who ultimately gains the upper hand both in his powerplay with her, and in his tussle with Mycroft and the establishment. And whereas Irene marries another man in the original – Holmes being reduced to a marriage witness – here she remains free to act as an object of Sherlock's fascination, with her ambiguous sexuality also mirroring his indeterminate sex life.

Sentiment might be criticised as a weakness, and as the mark of a loser, but sentiment is threaded through this episode's ending nonetheless: it's a screenplay that aims to be crowd-pleasing in almost every way imaginable (even Molly is treated marginally less abominably by Sherlock as he begins to realise the need to show her some basic humanity). But at the same time as aiming to please, this episode shows a keen self-awareness of the codes and conventions that it draws on. This is most notable, I'd say, in the use of assorted “boring” cases at the very beginning. Typically, it'd be assumed by unwitting viewers that such cases would constitute mere background colour coming before the real plot kicks in. It's an assured piece of Moffatesque misdirection, playing expertly with audiences' expectations.

It is probably Lara Pulver who has the most difficult task here – while the rest of the lead actors can already draw on funds of audience goodwill, and on their well-established performances, it is Pulver who has to conjure up a new take on an old favourite. Her Adler combines delicate elegance with predatory toughness, resulting in a glassy, brittle rendering of damaged humanity. Her sexuality is sketched in though barely explored, giving a further sense that despite her exhibitionism and extreme self-confidence, this Irene keeps her true self as buried and as hidden as possible. Benedict Cumberbatch and Martin Freeman again make their portrayals appear effortless, masking all the craft and thought that must underpin the seemingly just-so. And Mark Gatiss shines once more as Mycroft, with Moffat's script giving all of the leads some great material to work with (bar Rupert Graves, who is somewhat marginalised).

I hope to be proven wrong – and, after all, it's a capital offence to start theorizing before one has all the data – but I suspect two important things may already be true. First, this instalment might well end up being the high point of Sherlock series one and two. And secondly, this may be the TV drama high point of 2012, despite its broadcast falling on the very first day of the year. To be sure, it sets an incredibly strong precedent for Gatiss's pursuing hounds and Thompson's concluding fall to live up to. (Am I alone, I wonder, in feeling some fan anxiety about Steve Thompson's finale, given his track record with 'The Blind Banker' and 'The Curse of the Black Spot' on Who?). Paul McGuigan, like Steven Moffat, ups his game just when you thought that such a thing was pretty much impossible, and Toby Haynes surely risks being overshadowed across this run (as was Euros Lyn on series one).

Does this ninety minutes mark Sherlock's greatest of games? Perhaps. And although it would mean a greater-than-usual divergence from the works of Arthur Conan Doyle, I for one would favour a rapid Adler-Holmes rematch. Never mind the case of 'The Geek Interpreter', here's to the brilliant geek interpretations that I'm sure will rework, reshape and recode 'A Scandal in Belgravia'.