My eventual reaction to the final scene of this episode was pretty simple:
I feel like the real title of BBC Sherlock should be "Sherlock Holmes: Special Treatment." Or perhaps, "Sherlock Holmes: No Consequences."
— Hello, Tailor (@Hello_Tailor) January 13, 2014
I love Moriarty, and I'll be psyched to see more of him next
season. But his presence is indicative of one of Moffat's worst flaws as
a writer: his complete inability to allow serious actions to have
serious consequences. Sherlock coming back from the dead is a given, but
Moriarty recovering from a gunshot to the mouth? Although, I suppose,
he may not actually be "alive" next season. Perhaps he's committing
crimes from beyond the grave. Luckily for the purposes of this review, there's another extremely obvious
example of the total lack of consequences in this show: Sherlock's
near-instant return from "exile" at the end of the episode.
My
immediate assumption after Sherlock shot Magnussen was that next
season, we'd be in for some kind of Hannibal-style crimesolving scenario
where Sherlock is incarcerated but is occasionally sprung from jail to
help solve the puzzle of the week. This would be an interesting development both for Sherlock as a character and for the show, because the reason why everything seems like such a hot mess right now is because there are no restrictions on anything. Sherlock has too much freedom, the writers have too much power, and everyone would benefit from cooling their heels in narrative prison for a while. 



