NOTE: Full spoilers for this episode of, “Sherlock” are present in this review
Sherlock’s Series Four has been pretty uneven, trailing the former seasons’ higher quality pretty noticeably. Fortunately though, this week’s season finale, “The Final Problem”, was a very thrilling and mostly solid way to end the fourth season, even if the storytelling really starts flying off the rails here, and doesn’t quite stick the landing with its baddie. Even then though, maybe Sherlock’s growing detachment from reality no longer matters, since the show’s future overall is currently uncertain, with The BBC having not yet confirmed if a fifth season is happening, particularly due to the ever-busy film careers of both Benedict Cumberbatch and Martin Freeman at this point. If this does indeed end up being the final episode of Sherlock however, it’s a pretty satisfying farewell for this show’s established characters, even if the mighty Eurus Holmes has a few problems as an ultimate villain.
Fortunately, now that we’re done with grieving over Mary, as was a big focus in the season’s previous two episodes, this episode was left to focus purely on a fun and intense climax for the renewed partnership between Sherlock and John. For the first time this season, John is back at Sherlock’s side in this latest mystery, with Mycroft even tagging along, after a humourous intro with a fake haunted house-style ploy has Sherlock learning from Mycroft that he definitely has a long lost sister. Mycroft apparently knowingly kept Eurus stashed at a facility called Sherrinford, which is actually an island prison for the world’s most dangerous masterminds, though kept her accessible for himself, since she helped the British government thwart a few terrorist attacks, in exchange for some, “Treats.”
One of these, “Treats” however was five minutes of unsupervised conversation with Jim Moriarty (thankfully giving us a great appearance for Andrew Scott’s brilliantly entertaining criminal genius in a flashback), which explains how Eurus got ahold of Moriarty’s likeness, and could spread the false idea of Moriarty’s return to all of Britain. This somewhat implies that Eurus had a hand in Moriarty’s crimes and actions towards Sherlock in the first two seasons, especially since this Moriarty trick ultimately serves as a taunt that goads Sherlock, John and Mycroft to Sherrinford, after they narrowly survive a motion-activated grenade dropped by Eurus via drone that obliterates Sherlock’s apartment at 221B Baker Street!
As exciting as this first act is though, it does draw attention to one of the major issues with this episode; There’s several highly noticeable plot holes in it. Despite a bomb obliterating their apartment, and Mycroft having to jump down the stairs while Sherlock and John jump out the windows, it’s never ultimately explained how any of them survived, least of all without a single scratch on any of them! Even considering that Sherlock somehow survived jumping off of a tall building at the end of Series Two, this is a pretty big thing for the show to gloss over. Moreover, the cliffhanger from the previous episode is ultimately swept under the rug pretty fast, with Eurus apparently shooting John with a tranquilizer, the aftermath of which is never shown. It’s also never clear how Eurus could so easily move between her island prison and the mainland without ever arousing suspicion from anyone, and most conspicuously of all, the broadcast around Britain of Moriarty’s face at the end of Series Three is never ultimately explained either. Sure, Eurus did it, but how did she do it? The show never says. It really seems like the showrunners are thinking that this will be Sherlock’s last episode, so they completely gave up on any remaining semblance of being realistic here.
This is also extremely evident with Eurus, who is a very over-the-top intellectual juggernaut that humbles even Sherlock and Mycroft, with a seemingly supernatural ability to, “Reprogram” and manipulate people. Rather than feeling grounded and truly chilling though, Eurus is essentially an over-the-top comic book villain, complete with what are basically mind-manipulating superpowers. Granted, Sherlock’s extraordinary mind has more or less been treated as a superpower on this show before, but there was always a clear method and explanation for how Sherlock’s mind solved a problem, and it had at least some basis in actual scientific deduction. Eurus however might as well be Kilgrave from Marvel’s Jessica Jones, since she inexplicably has the entire Sherrinford staff in her pocket, and seems to have a limitless ability to influence whatever and whoever she wants. Like I said, it’s as if the showrunners have completely stopped caring about grounding Sherlock in reality at this point, and are just going for broke with another melodramatic storyline that is just going to do whatever it has to in order to get a rise out of the viewer.
To be fair though, if you suspend your disbelief and accept the absurdly overblown intellect and influence of Sherlock’s and Mycroft’s little sister, this is a legitimately thrilling edge-of-your-seat episode that truly does put Sherlock, John and Mycroft through a great emotional crucible. After the three go to Sherrinford and find Eurus, they end up trapped and forced to play a series of head games, each involving emotional context. In order to ensure their co-operation, Eurus has also knocked out every passenger on a plane except for a little girl mid-flight (it sounds like another outlandish plot hole, but believe it or not, Sherlock does actually explain this one), and is demanding that Sherlock and co. solve Eurus’ challenges to save the plane and the little girl. This involves having to watch a man die, judging a series of criminals, probing the feelings of Molly, and eventually, the ever-predictable choice of making Sherlock choose who means more to him; His brother or his friend.
Watching Sherlock, John and Mycroft writhe and struggle through these challenges is nicely unpredictable and exciting, and this also takes an unexpected turn when Sherlock responds to the challenge of having to kill Mycroft or John by preparing to kill himself. This has Eurus abruptly terminating her game, and bringing everyone to the Holmes estate in Musgrave, which, if you’re counting, is pretty much another plot hole, since it’s never explained how Eurus was able to move them there in a matter of hours. Regardless, this has Sherlock confronting the truth about Eurus drowning his dog when they were children, which, along with Eurus burning down the estate, led to her being sent away to Sherrinford in the first place.
Turns out, ‘Redbeard’ was not a dog however, but was in fact Sherlock’s childhood friend, Victor Trevor. The murder of another child versus a dog better helps to explain why Eurus was sent away, and it also has the added benefit of explaining a huge chunk of Sherlock’s social difficulties. Sherlock was repressing the memory of his sister killing his only childhood friend, which led to him socially distancing himself from everyone else. This was actually a pretty good twist, and it made John feel more important than he’s ever been on this show, while also filling in the claim by Mary that John is the only one who can, “Save” Sherlock.
Like I said however, this episode’s ending doesn’t completely stick the landing, since the girl on the plane is ultimately a fiction made up by Eurus (which explains that impossible scenario), who is actually delivering something of a cry for help that only Sherlock can understand. Also disappointing is just how much Eurus is deflated as a villain in the final moments, since Sherlock solves her, “Final problem” to find her cowering in his room, desperate for social connection. Immediately, Eurus goes from being an unrealistic, yet genuinely compelling super-villain, to a scared, crying girl who just wants her brother to help her. It’s tough not to feel let down by that, since it basically leads to the episode shrugging at all of the people that Eurus killed, and shrugging at her seemingly having a hidden hand in Moriarty’s legacy.
There is a definite sense of finality and resolution to the ending of the episode though, as Mycroft finally lets his parents see Eurus, who now plays violin with Sherlock from Sherrinford, while Sherlock and John start rebuilding their destroyed apartment and detective business at 221B Baker Street, as a final posthumous monologue from Mary confirms that Sherlock and John are right where they need to be, solving crimes and being the last desperate hope of a crazy modern world. It’s not a bad note to end the show on if this really is the last episode, especially with Sherlock resolving a key social trauma that lets him connect with people like a proper person now. If, “The Final Problem” is indeed the series finale, and we don’t ultimately get a fifth season of Sherlock, I’d honestly be content with that, and I doubt I’m the only one. Besides, I don’t know how the show is ever going to top an antagonist that can literally control people’s minds.