Sherlock series 3 finale review: His Last Vow

This review contains major spoilers. Our spoiler-free review is here.

3.3 His Last Vow

Let’s divvy up the winnings then, who had ‘rogue Secret Service assassin living under an assumed identity’ in the Mary Morstan sweepstakes?

Wrapping His Last Vow around the newly arrived Mrs Watson, taking her from ally to foe and back again, was a satisfying and thrilling end to Sherlock’s third series. Forget delaying gratification, this was revelation after twist after revelation after twist (with helicopters, shootings, and Bond villains to boot). Anyone wondering where the plot and jeopardy had gone in the previous two episodes now has their answer: it was all here, waiting to make a big showbiz entrance.

What worked so well about the Mary revelation is that it changed everything and nothing. By the end of the episode, she and John – Mr and Mrs Psychopath – were still in love, married, and expecting a child. Mary’s allegiance had been called excitingly into question but ultimately – like Sherlock – everything she did in His Last Vow was to keep John Watson safe. Planning to, but stopping herself from, killing Magnussen, shooting, but not killing, Sherlock… it was all to protect John from her truth and lies, both of which she thought would break him. (Not marrying him, of course, would have offered the best protection, but what was it Sherlock said last week about love standing opposed to pure, cold reason?)

The careful character work of the previous two episodes paid off richly in this, with Sherlock fulfilling his titular promise to always be there for his friends in dramatic style. Martin Freeman and Amanda Abbington cemented John and Mary’s until-now unexplored relationship in the series with some truly affecting scenes. “The problems of your past are your business. The problems of your future are my privilege” is 2014’s (much wordier) “You had me at hello”.

Singling out praiseworthy performances from such a well-matched and talented cast would take up the rest of the word count, but special mention has to go to Lars Mikkelsen, whose Charles Augustus Magnussen was a rare kind of bastard.

Granted, we heard more speeches about Magnussen’s villainy than villainy we saw, but the face-licking, eyeball-flicking and fireplace-pissing all did their work. Mikkelsen made an altogether quieter villain than Andrew “Miss me?” Scott (more on him – zoiks! – later), less mad but just as bad. Magnussen’s role as modern-day bogeyman the newspaper mogul made him especially easy to despise and continued the thread of tabloid-bashing Sherlock started with the character of Kitty Riley in The Reichenbach Fall.

Magnussen’s Robocop-style read-outs being down not to Google Glass but his mental acuity (“I have an excellent memory” indeed) was another great twist in an episode full of them. Learning that the basement glimpsed at the end of The Empty Hearse existed only in the blackmailer’s mind was the best kind of reveal: outlandish-sounding at first, but looking back, loudly advertised throughout the episode. His Last Vow spent so long showing us around the complex architecture of Sherlock’s mind palace that we should have seen it coming that Magnussen’s vaults would also turn out to be figurative. Perhaps you did. (Incidentally, and correct me if I’m wrong here, but does that make Magnussen the only villain in fiction to best the hero using… metaphor? Well done that man.)

Locations-wise, those “empty houses” at Leinster Gardens were a fun real-life addition, and Magnussen’s stunning modernist mansion may have had the whole Bond thing going on, but Sherlock’s subconscious was the one with all the surprises. Director Nick Hurran (The Day Of The Doctor) and Arwel Wyn Jones’ production design team took us further into the character’s psyche than ever before, past a dearly departed family pet (the Redbeard of The Sign Of Three), sibling-inflicted childhood trauma, and a padded cell containing a chained-up nemesis (zoiks! once again). Sherlock’s freeze-frame and balletic fall as mind-palace Molly talked him through his post-bullet options was bravura television. The visual flourishes had real narrative justification this time. Sherlock wasn’t just being flashy for style’s sake, it was telling its story.

That story was noticeably more serious than either of the previous two but Steven Moffat’s clever script still found time for laughter. The scene in which Sherlock attempts to convince John of Magnussen’s extreme evil but is unable to distract him (and us) from the reappearance of Janine – who, in her Sussex bee-keeper’s cottage, remains forever a romantic possibility for the Great Detective’s eventual retirement – was a treat.

So too, was the introduction of Bill Wiggins, leader of the Baker Street Irregulars in the Conan Doyle stories, as a junkie wannabe sleuth. There was plenty more fun: “Shezza”, “Sherl”, “Shag-a-lot Holmes”, all that Smaug-referencing dragon talk between the Holmes brothers (more like Niles and Frasier Crane than ever now, what with having a genius for a mother).

Better than the jokes though, were the surprises. List them all and you’d get writer’s cramp. Sherlock using, Janine emerging from the bedroom, Mary’s secret identity, Mary shooting Sherlock, John stepping out of Sherlock’s shadow, the truth about Appledore’s vaults, Sherlock killing Magnussen, Sherlock’s plane turning around after that Casablanca-style landing strip goodbye, and of course, the reappearance of Jim Moriarty. Is he actually… Does that mean he wasn’t really… Was it even him who…

Do you know what? Let’s leave the speculation for another time. Sherlock and John aren’t the only addicts here. The cleverest, most entertaining show currently on TV is over once again, and Lord knows we’re going to need something to tide us over until our next fix.

Read our review of the previous episode, The Sign Of Three, here.

Sherlock series 3 comes out on Blu-Ray and DVD on Monday the 20th of January and is available to pre-order at the BBC shop, here.

Follow our Twitter feed for faster news and bad jokes right here. And be our Facebook chum here.