In a Scandal in Belgravia, Sherlock leaks the secret to Irene about Mycroft’s plan to thwart Moriarty’s jumbo jet bombing. For this blunder, Mycroft could have had Sherlock’s head on a platter for being his biggest security leak in the entire United Kingdom. But Sherlock attempts to make it up to Mycroft and save him the trouble of not only losing his job but putting the citizenry in jeopardy by finally calling Irene’s bluff and giving his brother the upper hand back

How very unfortunate that Mycroft’s payback would, in his mind, cost Sherlock his life.

Moriarty somehow got Mycroft to believe that he was getting information from Moriarty by telling him the Holmes Family history and the childhood secrets of his dear little brother. But because of Mycroft’s thirst for Moriarty’s plans, Moriarty was able to glean the truth so that he could craft the perfect lie. Mycroft was now the one who would cost his brother that he worried so constantly about not only his livelihood, but his friends, his dignity, and his very life.

Mycroft probably wished he was dead after the Fall.

Gahhh so many feels.