Warning: spoilers that are also not spoilers.
Having begun with a brief recap of previous events—Sherlock on a roof, lying, jumping—we then see the first outrageous suggestion for how he managed to not die. It involves a mask and a bungee rope, the stage hypnotist Derren Brown, a broken window and a snog with Molly.
It’s nonsense, of course. Just one of many theories as to how Sherlock may still be alive, put about by a clan of fans, including a newly-bearded and guilt-ridden Anderson (there’s another one later in which Holmes and Moriarty giggle and then kiss). And Lestrade is having none of it.
What we do find out is that Moriarty’s plans to discredit Holmes have all come unravelled, that a police investigation has cleared his name. Meanwhile, John Watson has grown a moustache, and is struggling to leave his old life behind, despite having met someone similarly special: his new girlfriend Mary.
Then we’re in the woods of Serbia. A chase is underway, and a long-haired man is caught, taken to a lock-up and tortured. Then something odd happens. Through a fug of pain and lack of sleep, the chained man deduces that his attacker’s wife is having an affair. This changes things somewhat, as does the revelation that the man’s other guard is actually Mycroft Holmes, and that the man is his younger brother Sherlock.
No time for tearful family reunions, of course, there’s a terrorist attack planned on London, Sherlock is needed. The holiday is over.
So it’s a curiously apt time for John Watson to revisit 221B Baker Street, after two years. Mrs Hudson, who does not like John’s moustache, is cross that he hasn’t been in touch. They go and have a look at the flat, and John tells Mrs Hudson he plans to propose to his new love. Mrs Hudson expresses some surprise that he’s now interested in women, which goes down well.
In Mycroft’s office, Sherlock is having a shave and enjoying a little bicker, despite assurances that he’s about to try and foil a major terrorist attack on London. He doesn’t like John’s moustache either, but he does at least get his coat back.
Then it’s off to a swanky restaurant, Sherlock dedicates himself to ruining John’s proposal with a drawn-on moustache of his own. Amid a halting, tentative stab at making a heartfelt speech, the bumptious French waiter suddenly turns out to be… an old friend.
It does not turn out to be a friendly reunion. Quite the opposite, in fact.
A short while later, in a less exclusive establishment nearby, Sherlock begins to monologue his escape from death, only to be interrupted by a furious John, who, upon discovering that Mycroft and Molly Hooper (and Sherlock’s homeless network) all knew he was alive, proceeds to throw punches, and the tense trio are once again thrown out.
In a kebab shop nearby, Sherlock makes his big play: London is under attack, you’ve missed this, John, the two of us against the world…
John, now beyond fury, interrupts this tosh with a headbutt to the nose. And they’re out on the street. As John calls a cab, Mary promises Sherlock that she will talk him round. And why? Because she likes him.
Time to reappear, then. A quick visit to Molly first, then Lestrade, who finally gives Sherlock a hug, and then it’s back to Baker Street to thoroughly freak out Mrs Hudson. And then, with a news report and a hashtag, Sherlock lives!
John’s moustache, however, has died.
Meanwhile, Sherlock has put his homeless network into action, trailing suspects in the terrorism case, while John goes to his job. While Sherlock verbally fences with Mycroft about his private life (and plays Operation), John’s donning rubber gloves, clock-watching, and pulling imaginary wigs off his patients.
So, what’s a detective to do, except replace John with Molly and carry on as normal. Lestrade has a case, in which it looks like they’ve uncovered the final resting place of Jack the Ripper. Except everything is a bit too recent, and the ghost of John Watson is interfering with his concentration.
Then they pay a visit to a train enthusiast with an intriguing video. A man gets on an empty train, travels one stop, and vanishes. As has the driver of the train. But there’s nowhere for him to have stopped. And he seems oddly familiar…
While Sherlock is cogitating (and sharing a tender thank-you-and-goodnight moment with Molly), John goes back to Baker Street, only to be attacked, injected and abducted. He’s been tied up in something green and bushy. A bush?
Mary gets a text, a coded message (that she solves) and takes to Sherlock. He borrows a motorbike and the two are off to the other side of London on a rescue mission. There is not really enough time to get there, and frankly the roadblocks aren’t helping.
But where IS John? He’s inside a bonfire! A bonfire they’re about to light! And where’s Sherlock? Still on the bike. Thankfully the fire won’t light, so there’s a small delay as a man pours gasoline on, and then a torch. John’s on fire!
Oh no, it’s OK, Sherlock got to him in time. Just about. But no clues as to why it happened.
The next day, Sherlock is entertaining visitors (his actual mum and dad!) when John arrives. Turns out they knew he was alive too. Not that a proper apology is forthcoming.
It also turns out the man on the train is Lord Moran, Minister for Overseas Development, and traitor. The reason he wasn’t on the train is because it was detached from the rest of the train. And it’s November 5th, the anniversary of Guy Fawkes’s failed terrorist attack on the Houses of Parliament, otherwise known as the Palace of Westminster.
Time to investigate the underground network in the Underground network.
Having discovered a lost tube station, Holmes and Watson go off in search of the lost train car (note: not carriage), and soon enough, they find it. And then they discover it’s not just a car, it’s a bomb. The whole thing, seats and everything.
Still, no problem for the great Sherlock Holmes, right? He can defuse a bomb, surely? Oh. It seems not. Two minutes and thirty seconds count down, Sherlock has refused to call the police, what is there left to do?
Mind palace? No. Scrabbling around underneath the bomb? No. Sherlock can’t do it. And finally he apologises properly. This prompts a very huffy and puffy awkward moment of forgiveness from John, as the seconds tick down.
Briefly, we spend a moment listening to Sherlock to Anderson explaining how he survived the rooftop experience with Moriarty—a huge effort, orchestrated by Mycroft, that seems to have been almost entirely for John Watson’s benefit—and we get to see Anderson’s sceptical response. So we still don’t know for sure. Oh, and Anderson was the one who faked the Jack the Ripper thing.
We’re back in the train, and Sherlock is giggling. Because he switched the bomb off, ages ago. And he called the police too. Watson is not best pleased.
Lord Moran is arrested, the press gather outside Baker Street, and Molly turns up with her new boyfriend Tom, who looks strangely familiar.
Time for a glass of bubbly, and a deerstalker, and some grade-A showing off. Sherlock LIVES!
But why is that creepy man watching a loop of footage of John Watson get pulled out of a bonfire? There’s only one way to find out…
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