When I saw the first ten or so minutes of the show I thought for sure that Sherlock would go and accuse Culverton Smith based on the accusations of the man's daughter. That Holmes would be betrayed by the daughter and end up hospitalised (I had seen the hospital bed in the trailer). This would allow Culverton to kill him, which had been his plan all along. And then Holmes would prove he was correct using the modern equivalent of somebody standing out of sight and listening.
That wasn't how it turned out. As it turns out Culverton Smith had no idea about his "daughter" seeking out Sherlock Holmes or the detective's increasing obsession with him. There was no plan to set Sherlock up for failure which we might have seen with an earlier villain. All we had with Culverton Smith was an evil man who couldn't stop confessing and letting people know what he was while making it impossible for them to use his words against him. As villain's go he was a very simple rich bad guy.
E on the other hand... Now I stated a while back that I thought Sherlock had been mentally conditioned by Mycroft and that his older brother was slowly feeding him the key to memories he had suppressed. That made me wonder if Sherlock knows he has at least one other sibling (something about that line that people stop looking at three thinking although this could be yet another reference to the possibility that the 13th episode will by the last)? Do his parent know and what did Mycroft do? What did Sherlock do will be a more appropriate question I think.
So the episode ends with E or Euros (the East Wind) shooting John. I really can't wait to see where this goes.