Why does Sherlock still trust Mary?

 (Sherlock Meta by Loudest Subtext In Television)

I don’t think he does. Sherlock trusts her until the moment she shoots him, and then no more. We get a lot of indications that Mary shooting Sherlock is The Fall 2.0, and part of that is that Sherlock is feeding John another lie after. I address it in the HLV portion of M-theory in MUCH more detail, including Sherlock’s various possible hypotheses about Mary, but I’ll give a quick summary:

* We get the Bart’s rooftop color shift and fall music when mind palace Molly tells Sherlock “fall now.” (Credit to mid0nz for this, as always.)
* We get Moriarty in Sherlock’s mind palace, quoting directly from when he told Sherlock to jump off Bart’s: “One little push, and off you pop.”
* This time around, Sherlock ACTUALLY gives John his miracle and stops being dead.
* This time around, John is still in danger from a sniper.
* This time around, Sherlock has to sell John another hurtful lie: Mary is trustworthy.

How do we know Sherlock doesn’t trust her? Tons of reasons and tells:

* Sherlock only comes back to life because he believes Mary is definitely a danger to John. Moriarty in his mind palace says, “It’s [John] that I worry about the most. That wife. You’re lettin’ him down, Sherlock. John Watson is definitely in danger.”

* Moriarty put a sniper on John. Somehow, in Sherlock’s absence, John ended up with a sniper. And Sherlock knows what we say about coincidences: the universe is rarely so lazy. To believe that Sherlock genuinely trusts Mary, we have to think he’s beyond stupid. (In M-theory I also talk about the fact that Sherlock was nervous about that sniper, which is why he lied to Anderson about how John was totally safe the whole time. Of course John wasn’t safe. If John had been safe, Sherlock would have contacted him; he missed John like crazy and admits he thought about contacting him a lot. Mary isn’t the same sniper, but Sherlock doesn’t know that; he doesn’t know who any of the snipers were or where they were. If he’d known about them beforehand, he wouldn’t have sent John out into the open, he’d have had John hide deep indoors somewhere.)

* Here is the mind palace clip right before Sherlock flees the hospital. Mary does not look sweet and sympathetic in his mind: she looks cold, guarded, and calculating. He knows she shot him with the precision to merely incapacitate him him, and makes the sniper connection. If Sherlock genuinely trusted her, and just thought, “Oh, she only shot me because she loves John so much!” he would have just stayed in the hospital. After all, Mary could have killed him in the hospital and she didn’t, so Sherlock is safe there. Sherlock flees because he needs to ensure John is safe; after all, if Sherlock wasn’t supposed to find out about Mary’s cover, then for all Sherlock knows she has no reason to keep John alive now that the cat’s out of the bag.

* Sherlock has to act like he forgives Mary or Mary will kill him. She makes that very clear, to his face, before they head to Baker Street. I’m frankly shocked that anyone takes Sherlock’s forgiveness at face value when he’s under that kind of duress.

* Sherlock knows that Mary has had her current identity for five years, and it wouldn’t be lost on him that’s within the time frame of Moriarty messing with him. He doesn’t need to know Moriarty is alive to find that suspicious.

* Sherlock is clearly angry with Mary here, not sympathetic. When she says her selfish bit about lying to John so she won’t lose him, Sherlock looks like he can hardly conceal his loathing. He isn’t moved by her depth of devotion or something.

* Sherlock has to pretend to trust Mary for the sake of the baby, and to hide the fact that he’s on to her while he tries to figure out who she’s working for and why. He doesn’t want Magnussen’s documents merely to protect the baby, he also wants to know everything about Mary’s past. When Mary puts the USB drive down on the table, Sherlock fixates on it, which the camera makes very obvious. He’s not cool with the assassin thing, and he doesn’t trust Mary to give them all the information he wants.

* We get a clue that Sherlock is carefully controlling his emotions and reactions to John and Mary when he snaps at Mrs. Hudson, “Then what exactly is the point of you?” Poor Mrs. Hudson is the only person he can take his anger out on.

I’ll quote a longer bit from M-theory here:

Sherlock is going to go on to make excuses for Mary, but we keep getting these hints that he’s absolutely livid. Sherlock has no reason to be that angry at Mrs. Hudson or John. Sherlock is angry at Mary. Remember, even if this had nothing to do with John, Sherlock has a very particular moral code. This is the guy who won’t work for Mycroft because people like Mycroft start wars. We have never seen Sherlock kill anyone before this episode, and he only almost killed Moriarty when he thought it was necessary to save lives. But Sherlock ensured Mrs. Hudson’s husband was executed (and it’s worth remembering Mr. Hudson was used as a mirror for Mary last episode). Sherlock went all the way to Minsk only to gladly turn down an unsympathetic case and send a murderer to his death. Sherlock didn’t care about the guard in Magnussen’s office because he was a white supremacist. Sherlock stepped on the cabbie’s wound when he was bleeding to death and demanded to be given a name. In short, Sherlock would never approve of contract killing unless he could be certain Mary only killed bad people, and Sherlock has never cared if murderers die. If Mary weren’t carrying John’s child, she would be the kind of person Sherlock would leave to die without a second thought. She’s no better than the Golem, and Sherlock did try to kill him: he shot at the Golem repeatedly when he ran away, and was frustrated he missed.

Past that, Sherlock is angry Mary shot him in the heart instead of fessing up and asking for his help like a mature person. Sherlock is angry Mary pursued a relationship with John knowing it would be based on lies. Sherlock is angry that he has to convince John to stay with someone who has lied to John and isn’t worthy of him — Sherlock hardly considers himself truly worthy of John, so of course Sherlock doesn’t approve of what Mary’s done, and of course Sherlock would rather John be in a happier relationship than this.

* During the 221B scene, Sherlock shows impatience toward everyone in this scene from time to time, but John is the only one he ever is the least bit gentle towards. Sherlock is business-like with Mary, and looks at John like his heart is breaking for him. Which it literally is.

* Sherlock sees that Mary has not apologized and does not appear to do anything wrong, so he has to shift the focus on to John’s faults in order to get John to think he can never do better than Mary anyway, and to get on Mary’s good side. (I talk about this in great detail in the M-theory entry.)

Then I’ll just quote this bit from the M-theory entry, too:

Sherlock knows that John chose Mary because she wasn’t like that, and kept choosing her as an alternative to someone like Sherlock: John would have never bothered with things like therapy if he didn’t want to behave differently, if he weren’t struggling, and John always tries to present himself as more normal than he really is. Sherlock has seen that John keeps choosing a domestic life even though he hates it, which John wouldn’t do unless he felt he was supposed to. John was unhappy at the beginning of this episode because married life wasn’t dangerous enough, and that’s exactly what Sherlock had expected to happen. Sherlock was the one who pointed out that John was a danger addict looking for a fix that he hadn’t got from his marriage.

Sherlock knows that this situation is John’s worst nightmare, not something he asked for or should have predicted. Of course it isn’t John’s fault: if Sherlock couldn’t tell Mary was an assassin, John couldn’t have. As far as Sherlock knows, Mycroft and the whole British government couldn’t tell Mary was an assassin.

And even if it were all some sixth sense for danger, Sherlock doesn’t think John deserves something like this. Sherlock thinks John is the “best” and “bravest and kindest and wisest” man he’s ever known. No one could ever convince Sherlock Holmes that John Watson deserves this kind of pain.

Saying all this is literally killing Sherlock.

Moving on:

* When Sherlock says Mary befriended Janine to get close to Magnussen, and Mary says, “You can talk,” Sherlock gives her a weird, eye-twitchy half-smile. It’s very similar to the I’m-going-to-enjoy-ending-you smiles he’ll shower upon Magnussen at Appledore. It is not fondness or sympathy; Sherlock’s fond and sympathetic smiles are absurdly warm. [Clip.]

* In the same clip, when Mary says, “You did see that,” Sherlock looks distinctly uncomfortable. He doesn’t express agreement, he simply lets her say it. If Sherlock genuinely sympathized with her, he’d nod sympathetically — something, anything to back her up. But he doesn’t, because he doesn’t sympathize. Mary continues, “And you married me. Because he’s right.” We get another shot of Sherlock looking even more uncomfortable. This is exactly what Sherlock needs John to believe, and it’s working that Mary is going along with it, but he doesn’t like blaming John. “It’s what you like,” Mary finishes. And Sherlock changes the topic, visibly struggling with the literal pain in his heart as he asks about what Mary wants from Magnussen.

* Sherlock explains what happened at Magnussen’s office in the most sympathetic light possible: Mary really did intentionally incapacitate him, but Sherlock chooses to refer to that as saving his life when we know that Mary could have just accepted Sherlock’s help. Notably, Sherlock leaves out the part where he offered his help, because that would make the story unsympathetic.

* The whole conversation Sherlock just states his story and never once looks like he feels sorry for Mary or likes her at all.

* Sherlock tells us over and over the reason he detests romance is that it’s destructive: people hurt each other, and we’ve seen him be awful to clients who have lied to their spouses. Why would anyone believe Sherlock is suddenly cool with that behavior when it’s taken to the level Mary has taken it?

Also, note that the episode title is a play on the ACD story "His Last Bow." The majority of the episode is actually a retelling of “The Adventure of Charles Augustus Milverton,” so what elements of “His Last Bow” might be present here? Well, Holmes pretends to be on the side of a spy in order to get the evidence necessary to take him down, and chloroforms the spy in the process. That’s literally the entire story. In HLV, Sherlock pretends to be on Mary’s side so he can get the evidence necessary to take her down, and drugs her unconscious in the process. (I give all the evidence that Mary is Moriarty’s spy in M-theory.)

Then at the end, we get John asserting that Sherlock is the East Wind: Sherlock is the “terrifying force that lays waste to all in its path” and “seeks out the unworthy and plucks them from the earth.” Mary had better wrap up warm.

Hope that covers it. If we were supposed to believe Sherlock genuinely trusts Mary, we wouldn’t get all these hints that he, well, doesn’t trust her at all. And it makes a lot more sense that he wouldn’t trust her.