Forget the ambiguous solution to the Fall. Put the whimsical wedding episode behind you. Because Sunday night’s Sherlock finale is a scintillating return to form that will melt the Internet and drain the Monday-morning water-cooler within half an hour.
His Last Vow ticks all the boxes. For Sherlock Holmes sticklers, the episode is based solidly on an original Arthur Conan Doyle story and also makes meaningful use of plot devices and characters from elsewhere in the canon.
Sherlock fangirls will be squeeing throughout at twists, turns and revelations – and the cliffhanger ending might just make their heads explode.
Meanwhile, general viewers in search of a smart, thrilling adventure and great performances will be satisfied too.
Lars Mikkelsen manages to be simultaneously magnetic and repellent as master blackmailer Charles Augustus Magnussen, the man who believes he can own anyone he chooses. It's a scene-stealing performance from the Danish star better known to fans of The Killing as mayoral candidate Troels Hartmann. Look out for the shockingly casual way in which he desecrates Sherlock's Baker Street sitting room.
In an interview earlier this year, Martin Freeman joked that “the show’s not called John yet”, but after this episode it almost feels like it should be. The idea that Dr Watson is simply the everyman foil to the more flamboyant characters is called into question with a neat bit of analysis of John's psyche.
If there's a letdown, it's the denouement of the main story, which serves Mikkelsen's character poorly and makes Sherlock appear rather naive – but that will quickly be blasted out of viewers' brains by the mind-boggling final moments.
Sherlock: His Last Vow is on Sunday at 8:30pm on BBC1