Warning: This is a film analysis of the movie Mr. Holmes and will contain complete spoilers.
Mr. Holmes is a film about an aging Sherlock in self-exile. His age has brought on a senility that has caused him to forget so many of his cases, and the most important of all, the case that brought on his retirement. Through a gradual series of revelations we learn that his dedication to deduction, fact, and his own brilliance led to the allowing of a woman to commit suicide. The 'game,' as he commonly referred to it, was up, for a person's life hung in the balance.
The theme of the film is what Carter Burwell titled the last track of the soundtrack that he composed for the film: the 'Consolation of Fiction.' Mr. Holmes learns that his facts can and have hurt people, and thereby chooses fiction to console an individual at the end. However, the theme is explored in other, less direct ways.
From very early on in the film, the audience learns that all of the stories written by Dr. Watson, Sherlock's partner in deduction, were embellished. How embellished were they? That question is ever present in audience's mind, for we never really see any bit of brilliance from Sherlock himself until the climax. Whenever Mr. Holmes does a bit of deduction, there's always an alternative explanation as to how he was able to come to that conclusion. These explanations could lead the audience to think that maybe the whole Sherlock facade is an embellishment. For example, when the housekeeper's son asks how he knew it was the wife; was it because of a series of small details that he saw? No. When a husband came with a case, it always had to do with the wife.
What if Sherlock Holmes was nothing more than a charlatan? The smirk he wears in the flashbacks might suggest that. And this deception is almost solidified when he attempts to read the palm of the woman central to the retirement inducing case. After the ridiculous palm reading she confronts him, letting Sherlock know that she knows who he is and has been leading him on only to confront him. Could it be that him being exposed as a con man is why he went into retirement? Yet this ends up as another bluff by the filmmakers. An attempt to cause confusion as to what is fact or fiction.
Only at the climax do we glimpse that Sherlock Holmes is indeed the master logician that we know from the stories. He knows exactly what the woman has been up to and that it was all a show for him. However, as it turns out, she performed her dupe because she knew that the only person in the world who could understand her was the brilliant Mr. Holmes. And his exposition into her condition and his inability to see the truly dire nature of the situation caused, or at least failed to prevent, her subsequent suicide.
So, Mr. Holmes now hates himself and has chosen self seclusion for the sole purpose of not hurting anyone else. He saw that he had abused his talents in making his work a game. At that point he concludes that while fact and truth had once been his greatest allies, they are now his greatest enemies.
Of course this journey that we make with Mr. Holmes is so much more compelling because we are making the discovery with him. In his old age he has lost this particular life changing memory and spends the better part of the film trying to remember it.
