SHERLOCK: SEASON 4

2015’S SHERLOCK CHRISTMAS special, ‘The Abominable Bride’, proved divisive: a mash-up of horse-drawn Victorian melodrama and Inception-esque mind-trickery, it pleased some and made others fling their remotes across the room. The show returns to steadier ground with ‘The Six Thatchers’, this opener for Series 4, a comparatively straightforward mystery, but one which still manages to fit in sharks, a paramilitary snatch team, Tibet and the titular British PM. Most impressively, it shows tonal control, as it starts light and breezy, slowly sliding into darkness and climaxing with perhaps the most combustive bombshell to date. And no, it’s not that Sherlock has finally bought some tasteful wallpaper.

As it opens, Benedict Cumberbatch’s Holmes is, very amusingly, experiencing PMWS (Postmoriarty Withdrawal Syndrome). With his bête

noire vanquished, he should be kicking back with a scientific journal, but instead he’s gone into hyperdrive. More specifically, he’s logged onto Twitter. Tapping up a frenzy — and even coming up with his own hashtags (“#221Bringit”) — he’s solving cases in 140 characters or less, even during classified briefings, much to the chagrin of his brother Mycroft (Mark Gatiss). Martin Freeman’s Watson, meanwhile, is adapting well to fatherhood; as he points out, having Sherlock as a partner is excellent preparation for looking after a pissy, self-centred infant. His marriage to ex-spy Mary (Abbington), on the other hand, is perhaps not going quite so well...

Based (extremely loosely) on Arthur Conan Doyle story The Adventure Of The Six Napoleons, the tale retains such classic elements as the black pearl of the Borgias and a set of busts of a famous figure, which are being tracked down and smashed by a mysterious n’er-do-well. (The élan with which the likenesses of the Iron Lady are wrecked on screen suggests showrunners Mark Gatiss and Steven Moffat may have enjoyed those scenes.) True to Sherlock form, however, the case veers closer to home than is originally suspected. Sherlock is at its best when there’s a devilish villain tormenting our heroes, whether it’s Andrew Scott’s impish Moriarty or Lars Mikkelsen’s serpentine blackmailer Charles Augustus Milverton. Series 4 promises to add a humdinger to this line-up, with a blondbarneted psychopath played by Toby Jones. But that’s still to come. ‘The Six Thatchers’ does have a bad guy, but he’s very much in the background. Instead, the episode focuses on the cracks starting to form between Sherlock, John and Mary. The emotional events of the final act change the dynamic of the show irrevocably; it will be fascinating to see where it goes from here.

With all the darkness — and this episode gets pretty darn dark — Gatiss and Moffat make sure to keep a current of fun fizzing through it. This comes in the form of wry revelations (it turns out Sherlock instantly deletes any text message that begins with “Hi”), callbacks to Doyle (Toby the bloodhound, from The Sign

Of Four, finally makes an appearance) and bold bits of production design (the visual motif for this week is “sharks”). Energetic, smart, finely polished and just a little pleased with itself, it’s quintessential Sherlock. The boys are back in town.

VERDICT A very solid return to modernity for Watson and Holmes, with a dab of silliness, a smidge of globetrotting, and a shocking ending that might just give you sleuth-ache.