In our big-bang globalised environment, Sherlock Holmes is now more like a Marvel Comics superhero than a mere "consulting detective". We take it for granted that his deductive powers can peel open the physical and psychological secrets of a complete stranger within milliseconds, while the scope of his ambitions has advanced from solving quaint Edwardian mysteries to unpicking global conspiracies and phantasmagorical terror threats. The game is afoot, but now it's in fibre optic HD 3D with 7.1 surround sound and added social networking.
Happily, Mark Gatiss (who wrote this series three opener) is canny enough to recognise the value of wit to humanise the cascading cleverness, and even amid the quicksilver torrent of tricks and feints he made sure that the Holmes-Watson relationship continued to strike sparks. Much - possibly a little too much - time was allotted to Watson's coming to terms with Holmes's return from the apparent dead (he was particularly miffed that the select handful of people in on the secret hadn't included him), but the chippy, bantering rapport between Benedict Cumberbatch's mercurial Sherlock and Martin Freeman's stolid Doc is among the best in the long history of their screen incarnations. Clever-clogs Sherlock getting a head-butt and a bloody nose from his exasperated assistant seemed only reasonable.
Gatiss (pictured as Mycroft Holmes) had evidently burned wallet-piercing quantities of midnight oil over the feverishly-debated issue of how Sherlock had survived the long drop off the roof of Barts hospital onto the unforgiving pavement below at the end of the last series. Cunningly, he gave himself extra wiggle room by supplying the solution in binary form. First there was a kind of touristic version, involving rubber masks, bungee-jumping and a guest appearance by Derren Brown. We saw this one being relayed to DI Lestrade (an endearingly dog-eared Rupert Graves) by conspiracy nerd and Holmes swot Phillip Anderson (Jonathan Aris, in need of a good bath). Lestrade's reaction - "Bollocks!" - will have struck a popular chord, I think.
Reminder: what happened in the finale to Sherlock series two
Sherlock Holmes on theartsdesk
Version two came from Sherlock himself, and was delivered to a salivating Anderson with smirking triumphalism by the too-clever 'tec. I shan't bore you with the details - you can look 'em up on iPlayer - but Sherlock couldn't conceal his displeasure when Anderson declared himself "disappointed" with the explanation. "Hmmph, everyone's a critic," grunted Holmes. So there we had it - two explanations, each of them nearly as trustworthy as a politician's election promise.
It was excellent sport of course, though all this restitching of the narrative fabric - we also had the reintroduction of Una Stubbs as landlady Mrs Hudson and the arrival of Amanda Abbington (pictured left) as Watson's fiancée, Mary - meant that the episode (albeit lasting 90 minutes) had to get its skates on to fit in a bit of new plot. This involved Sherlock being captured and horridly tortured in some Balkan hellhole, then, thanks to an intervention by his super-competitive brother Mycroft (Gatiss himself), whisked back to London to foil a fiendish plot by an "underground network". Since we're in the wordplay business here, underground turned out to mean Underground, featuring an explosive-crammed tube carriage designed to pick up where Guy Fawkes got off.
The closing seconds offered an oblique glimpse of new villain Charles Augustus Magnussen, played by familiar Danish actor Lars Mikkelsen (Katrine's new boyfriend in the last Borgen). All, or at least a bit more, will be revealed over the next couple of Sundays.