[This is a review Elementary season 2, episode 23. There will be SPOILERS.]
The threat of relapse is a considerable part of the tension that goes into making a recovering addict's story interesting. No matter how well things are going elsewhere for the character, the notion that he or she is just one bad day away from losing their sobriety is the kind of looming threat that can considerably disrupt whatever semblance of normalcy or stability that was achieved prior. That is certainly a large part of what the Elementary season 2 finale was getting at with 'The Grand Experiment,' and the manner in which it sought to ultimately threaten Sherlock's sobriety also granted Joan a more active role in her own character arc.
On the surface, the finale was dealing with the threat of Mycroft being accused of treason and murder, and Sherlock's attempts to prove that his handler, Sharington (Ralph Brown) was the real culprit. But the last few episodes had been building toward the larger, status quo-altering shake-up that was Joan's decision to move out of the brownstone she shared with her partner. Early on, Joan's desire to find some sanctuary from the provisions Sherlock has for the relationship was kick-started by the somewhat flat relationship her character developed with Mycroft. But soon, as the story line became embroiled in Mycroft's increasingly complicated MI6 dealings, the decision began to mercifully feel more and more like one Joan was making in an effort to further her individual growth, rather than simply support and nurture another relationship with another Holmes boy.
That decision is wonderfully expressed around the finale's midpoint, while Sherlock is in the middle of investigating the murder of an Iranian national, who, in turn, wound up being tied to Sharington's treasonous efforts. Like everything else that has been going on in the last few episodes, the scene is about Sherlock and Joan, only far more overtly and without the distraction Mycroft's presence typically brings. It's a great scene in which Sherlock essentially spells out the fundamentals of why Elementary actually continues to work, and why maintaining the aforementioned status quo would be of great benefit to not only himself and, at least from his point of view, Joan, but also the viewers. In that way, it's as if the show's writers are openly expressing the dangers of getting too comfortable with the cozy interplay and growing normalcy of the protagonists' relationship; they had become a functional couple and as pleasant and reassuring as that is to check into on a weekly basis, it isn't the sort of thing that a dynamic drama is necessarily built on. That sort of thing certainly helps the procedural aspect of the show function, but to its credit, Elementary has always seemed more interested in the story roiling underneath whatever else is going on from episode to episode.
For her part, Joan chooses to acknowledge the tremendous draw that is Sherlock's genius – likening it to the gravitational pull of a planet, and thereby suggesting she's like a moon caught in his orbit – while holding firm on her decision to seek a place of her own. That decision, then, marks a dramatic and necessary change for Watson's character as an individual who serves as something more than the genius' confidant or chronicler of his exploits. It's a shift in the paradigmatic scheme of this iteration of the Holmes formula, one that pushes Joan into an independent role, someone who is already Sherlock's peer, and is, most importantly, capable of expressing and acting upon her own desires independent from Sherlock's.
That change in Watson, in addition to the events that take place concerning Mycroft's role in MI6 and his reasons for still being there all seemingly drive Sherlock to make two potentially destructive decisions that will undoubtedly impact the series as it pushes into season 3. Certainly, there is no physical proof that Sherlock has used the heroin he pilfered from a crime scene, but the implication is there, and it is certainly reinforced by his decision to take MI6 up on their offer of employment. That mixture of the implicit and explicit, in terms of reactionary self-destruction on Sherlock's behalf, works quite well to bring the season to a close with a sense of further chaos and upheaval to come. The only problem is that the conclusion of the Mycroft story line doesn't seem to form an entirely convincing cohesion with the admittedly interesting jump that Sherlock makes.
Much of that stems from the fact that while Elementary did a solid job bringing Mycroft back and setting up a compelling arc, the character was ultimately pulled in three directions at once, ostensibly being asked to fulfill the emotional needs of Sherlock and Joan, while also serving as a plot device for the overall narrative. It was an ambitious idea, but one that would likely have been better served had Mycroft been a more constant presence over the course of the season. Ultimately, his various threads wound up feeling too much like a series of convenient catalysts, while his departure at the end was little more than an ellipsis on his story, rather than a more definitive period. The open-endedness of his story is necessary, as Mycroft is a character the series will likely use again, but the manner in which his MI6 problems were resolved didn't necessarily afford the character or the story the kind of denouement that brought all the other threads to an enticing conclusion. Underlining the haste with which Mycroft used the NSA to free himself from the clutches of British Intelligence was a nice call back to 15-year-old Sherlock's assessment of his brother, but perhaps it facilitated Mycroft's exit too easily.
Although the two distinct threads of the finale didn't necessarily align in a way that was as fundamentally moving and powerful as last season, 'The Grand Experiment' definitely worked by – to borrow from Sherlock – providing the clay from which the bricks for season 3 will eventually be formed. Shaking things up can be a good thing where drama is concerned, and the promise of the season 2 finale suggests its importance will become greater when the series resumes in the fall.
Elementary season 3 will air in the fall of 2014 on CBS.