My first post to share my own Pet Theory There has long been a theory that there is a missed clue. I think the clue is simply the title. The whole episode is not about the fall of Sherlock, but the fall of Richard Brook, Moriarty. It rests on the final conversation between Sherlock and Moriarty. Moriarty asks Sherlock if he thinks that he can make him talk when his brother failed. Without missing a beat Sherlock say "but I'm not my brother" throughout the pretense is that Sherlock is unaware that Mycroft had Moriarty. But the conversation doesn't sound like this is a surprise.... Sherlock and Mycroft pushed Moriarty and manipulated him to a reliance on Sherlock. They knew that death was preferable to losing so that had to get him to choose death. He alone knows all the threads, so if dead then the web ceases to exist. The individuals in the web are still dangerous but the conspiracy will fail. Sherlocks fake death was twofold; protect his friends and to go after the threads incognito. Ties into IOU as Mycroft has been pushing Sherlock into becoming Moriartys nemesis, not the other way round. All the cases shown so far have been an elaborate trap for Richard Brook to fall. My 2 penny's worth