Their masks just drop. The instant Mary turns away, both their expressions change completely. For a fleeting moment, you can see their real feelings behind those fake smiles and empty promises. Bitterness, disgust, mistrust.
I see two people playing one another. And what’s more, I think they both know it. Sherlock tried to lull Mary into a false sense of security with his “surgery” explanation. For whatever reason, he needed John to trust Mary, to stay with her, it was vital John stay just where I put him. But that doesn’t mean Sherlock trusts Mary. It means he needs Mary to think she’s gotten what she wants. He needs her to think she’s in control.
But Mary knows what he’s doing. I’m not John, I can tell when you’re fibbing. Mary quietly sat back and allowed Sherlock to “deduce” her, explain how she saved him by phoning the ambulance…not only does she never once offer a single piece of information herself, she never even confirms or denies what Sherlock says. She sits there, blankly, taking it in and calculating how best to use what he’s giving her to work with.
Give Mary my love. Tell her she’s safe now.
I was so upset by that line initially. After all that, why did Sherlock want John to think he shot Magnussen for Mary? That he sacrificed his own life and became a murderer just for her? Then I realized…it’s not that he wants John to think that. It’s that he needs Mary to believe it.
The giant gap of time between the Great Watson Domestic at 221B and Christmas makes it so difficult to really come up with a solid theory as to what everyone’s motives were in the end. Here’s what we do know:
1. Mary and John weren’t speaking during those months. (She says so.) It’s very plausible they weren’t living together.
2. Therefore it’s also plausible John temporarily returned to 221B. (Remember when he realized Sherlock had moved his chair back? “Mrs. Hudson, why does Sherlock think I’ll be moving back in?” Sherlock didn’t expect them to clear things up that evening. He knew John would need some time.)
3. Sherlock wasn’t twiddling his thumbs during those months. Whatever his plans were with Mary, he was preparing.
4. Sherlock learned from Reichenbach that protecting John is one thing, but lying to him is another. He isn’t going to do that again, not if he can help it. He shared his plans with John, at least to some extent. (Sherlock usually withholds a few steps. John’s used to that by now.)
5. “These are prepared words, Mary. I’ve chosen these words with care." There’s no wasted dialogue on this show. John says this for a reason. I believe that, for whatever reasons, Sherlock helped him choose these words. Sherlock needed Mary to believe John was going to stay with her. But that doesn’t necessarily mean that was John’s intention. All I’m saying is, at this point in time, John is telling Mary he wants to work it out, and Sherlock knows that’s what he’s doing. Therefore this is part of Sherlock’s plan.
And personally, I don’t think he ultimately intended for John to stay with Mary, nor do I think John intends to. I truly believe Sherlock knows Mary didn’t perform surgery – that the reason she took a shot that was a probable, but not definite, kill was the nature of her paradoxical relationship with John. She will do anything not to lose John, but she needs the challenge of having to fight for him or she’ll get bored.
Sherlock knows the Watsons are doomed. Very likely John knows it too. I believe Sherlock intended on getting Magnussen’s files on Mary for the sake of John’s safety – removing any leverage Magnussen would have over Mary, and therefore John (the whole pressure point thing). And after that…who knows. But it was never going to be domestic bliss for the Watsons.
That’s why Sherlock’s decision to shoot Magnussen is so intensely heartbreaking. He realizes he’s made a huge mistake – there are no files to get. The only way to truly protect John is to become a murderer, essentially sacrifice his own life. So just like Reichenbach, Sherlock is put in a position where he had to make a huge sacrifice for John without telling him why. It’s too late to do anything else. Killing Magnussen means Mary will be safe, therefore John will be safe…but only if Mary is still convinced of Sherlock’s charade. And that, unfortunately, means convincing John, too.
I really believe that once Sherlock escapes the hospital, he has a long-term plan for how to handle Mary. But it went horribly wrong. Which is why, in this moment when they say goodbye at the plane, we briefly see his mask drop. It wasn’t supposed to happen this way. She wasn’t supposed to win.
And that’s also why John seems so off during the goodbye at the plane. Things went wrong at Appledore, but John simply can’t accept that it’s truly over. He’s waiting for one more miracle, anything. Sherlock doesn’t always fill John in on every step of his plans, and John’s used to this. He’s come to expect it. He can’t ask, not with Mary and Mycroft there, he just has to trust. So he does. He shakes Sherlock’s hand silently, watches him board the plane. Watches the plane take off. Starts to wonder if maybe he was wrong. Maybe there was no trick after all. It really is over. And then….miss me?
One more miracle.