So, after watching the episode twice yesterday....
First things first, I really liked the new episode. Mycroft got a lot more screen time, Mrs. Hudson reveals her true BAMFness, and Irene...worked, for me. This is also the episode that really cemented Sherlock's asexuality and his and John's relationship (for me, anyway).
The main thing I'd like to talk about is Mycroft. In this episode, we see a lot more of him, and I think it drove home the point that Mycroft is missing something just like Sherlock is (Sherlock says "do you think there's something wrong with us?"), except Mycroft is willing to act the part to blend in with the rest of society. "Caring is not an advantage. Sherlock." This spoke volumes to me about how the two brothers were raised, and possibly how Mycroft raised Sherlock (since I get the impression Mummy isn't that big an influence on Sherlock's life).
Also, in the end, about Irene's supposed "death" and Mycroft telling John that and so on... Here's the way I see it.
Mycroft knows the truth, he's Mycroft, of course he knows. He knows Sherlock went to save Irene, he knows Irene isn't actually dead, he knows the rest of the world thinks she's dead. Sherlock knows that Mycroft knows, because, hello he's Mycroft, he knows everything. Which means John is the only one in the dark about the truth. So, what is the purpose of the last scene?
Mycroft asks John to tell Sherlock that Irene is in the witness protection programme in America, then tells him the "truth" that Irene is actually dead. Then, he asks, "So what should we tell Sherlock?" When John gets back to the flat, he tells Sherlock that Irene is in witness protection, when Sherlock knows she should be dead to the rest of the world. He knows at once that Mycroft told him this, and he also sees that John knows the "truth" that Irene's dead (he can tell when John is lying, of course). The important thing here is not what John is telling Sherlock, but what John chose to tell Sherlock. John chose to lie to protect Sherlock.
Mycroft, of course, knows that John would choose to lie. He also knows that Sherlock would see right through the lie. If Mycroft truly believed Irene was dead, he would not tell John that, because he knows Sherlock would see right through John's lying, and demand the truth. So in this way, both brothers know that Irene is still alive, and they both see that John is willing to lie to protect Sherlock's emotions.
So why does Mycroft do this, when Sherlock already knows he knows? I see it as a gesture on Mycroft's part: "Look, you believe love is the downfall to everyone, yet here is someone who loves you still. He's not as smart as you or me, but he tries so very hard for you. Appreciate it." And Sherlock does.
Comments and thoughts on the episode?