Why did they have John beat up Sherlock in TLD?

 (Sherlock meta by Ivy Blossom)

Q: [...] Why do you think Mofftiss chose to have John beat up Sherlock in The Lying Detective? They didn't have to go there, right? What was the point of going that far, and then not even showing us the emotional 'pay-off' we assume happened before The Final Problem? Why do this if the point of the show is to portray the devotion between Sherlock and John and their journey to a legendary partnership?

A: Perhaps we can come at this by considering what narrative function John’s violence serves in the story.

First things first: an important part of John’s characterization is that he cannot express his most intense feelings in words. He doesn’t say the things he needs to say.

I don’t think you can overestimate just how much John hates himself in The Lying Detective. He has failed in every way that matters to him: he cheated on his wife (as far as he’s concerned), he’s abandoned his daughter. He’s drowning his sorrows in alcohol. He’s hallucinating. John is broken. He says nothing, which means he’s not yet completely broken.

The slow breakdown of John Watson isn’t just about Mary’s death, but that does bring it to a head. It’s also about the still-steaming revelation of Mary’s past and how she lied to him from tip to tail. He placed all of his faith and trust in Sherlock, and he failed to deliver. He feels betrayed, but unable to express that. He must accept things as they are because it’s the right thing to do, but he can’t do it. He hates himself for failing everyone he knows, and he hates everyone he loves for failing him. He is rudderless. Still: he says nothing. He hasn’t quite hit rock bottom yet.

And then he finally does.

When John breaks completely and hits and kicks Sherlock, he has been dragged into a case after forcefully pushing Sherlock out of his life, repeatedly reminded that he’s a failure even at the one thing he’s valued for (writing about Sherlock), and has to face that fact while waiting outside a loo while Sherlock gets high, literally on his way to killing himself again. Then he watches Sherlock apparently falsely accuse a man of being a serial killer and then threaten him with a scalpel. Sherlock is out of control too. It’s John’s job to keep Sherlock in line, isn’t it? But what good is he at that?

John is angry with Sherlock for letting Mary die, for betraying him, for failing to be the man John believes him to be. John hates himself for failing to live up [to] even a single one of his own standards. Hurting someone he loves, something he also did to Mary without her knowing it, is, I think, the ultimate expression of how broken he has become. He is there to protect Sherlock, but he does the opposite. It is his final and ultimate low. John is now utterly broken.

He does not apologize for his actions. Or at least, we don’t hear him apologize. He stands at the foot of Sherlock’s hospital bed and bears witness to the evidence of his rage, the damage he caused to someone he loves. How long does he stand there? We don’t know. How does he feel? Does he regret what he’s done? Is he ashamed of himself? He comes to say goodbye, but he can’t face a conscious Sherlock. He still can’t say any of the things that matter.

He walks out of the room expecting to never see Sherlock again. Mary forces John to admit that he can’t stop thinking about him. And that he hates himself. Is he sorry? I think he’s beyond sorry, but he says nothing.

Until he finally does.

I think the violence, the balled up emotions that never get expressed, are there to underscore the moment when they finally are. Finally, finally, when Sherlock asks John if he’s okay, he is truthful: no. He is not okay, and he will never be okay.

And then the floodgate is open. John says the things he never said. He asks the questions he always wanted to ask. Having reached the ultimate rock bottom, John is finally cracked entirely open. He is talking, and he is honest. And 221b blows up so that they can rebuild it and start over.

I think John hurts Sherlock in order to explode the part of him that holds him back. It is Sherlock’s guilt made flesh and blood, and it’s the action that pushes John to finally be brave to open his mouth.