When the Series 4 episode titles were first released, I was unsure what to think. Why would the creators of Sherlock name an episode after something previously mentioned in the series if not a direct callback to it. Hadn’t the final problem already been addressed on the rooftop of Barts Hospital? Was this somehow a clue into some sort of deeper meaning to that conversation before Sherlock fell? To be honest, it hadn’t hit me until this very moment what this episode title could actually be referring to.
I am a strong believer that TFP is occuring in John’s mind, there’s no way they would end on a cliffhanger with John being shot and then have him be totally fine, just having experienced a low level dart gun. The red rug that surrounded his feet in Eurus’ therapy office symbolized blood, and I don’t think that we should disregard that quite yet.
In The Reichenbach Fall, Moriarty says
Sherlock solves this predicament with the fall, but what if, at the end of TLD, John has the same problem.
The Final Problem is stayin’ alive and that is exactly what TFP is. John trying desperately to find a way to stay alive in his little old mind bungalow.
In His Last Vow, the thought of John pulls Sherlock up and back to life, in The Final Problem, Sherlock pulls up John.
It’s just Sherlock and John with a problem, the final problem, stayin’ alive.
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