Sherlock has been without a case before. He sulks, he does research, he fires happy faces into walls with bullets from a semi-automatic pistol. He whines and complains. But this time he seems out-of-control.1
Sherlock describes his mind
"... like an engine racing out of control, a rocket, tearing itself to pieces, trapped on the launchpad ..."
Trapped on the launchpad?
Mycroft and Sherlock secretly planned to take down James Moriarty, and with him, his web of operatives. But at this point, Sherlock must wait. Mycroft has Moriarty in custody, he is being "questioned." Only the two of them know they are working together, Moriarty obviously has agents inside the MOD as well as Scotland Yard. The flat is under surveillance.2 Sherlock has to act his part every minute of the day.
For now, it's Mycroft's turn, he is trying to extract information from James Moriarty. IF Moriarty breaks, they will have him and his gang. If not, Sherlock will go to work, undertaking his most dangerous assignment. Dangerous because Moriarty must believe he is the one controlling the action. He must be given free rein and, somehow, Sherlock will have to figure out step-by-step, moment-to-moment how to defeat him, when Moriarty's no. 1 priority is Sherlock's destruction.
|Sharing a smoke with Henry.|
Luckily, Henry Knight shows up to rescue Sherlock with a cigarette and a case, repeating one of the most famous lines in entire Canon, "Mr. Holmes, they were the footprints of a gigantic hound!"
|The devil according to Sherlock Holmes.|
If there is no Moriarty, is there anything in the episode besides the ending to give us clues to what's really going on?
Out of Character
|Startling Watson: "Hello, brother, dear... "|
|Watching Mrs. "Full Metal" Hudson terrorize Chattergee.|
Yet, in the previous episode, "A Scandal in Belgravia," we see Sherlock in the last scene saving Irene Adler's life in Karachi. One wonders at this point if the writer has a vacation home in Pakistan. In The Holmes Boys Stalking Moriarty, it's proposed that Mycroft met with John Watson in the cafe (also quite out-of-character) in order to plant false information for anyone who may be listening to the conversation. Is it significant? All we can say at this point is: nothing said in the flat or the cafe by Sherlock or Mycroft can be taken by the viewer as factual. Nor can we count on what Sherlock says privately to John who is also being kept in the dark about Sherlock's new partnership with his brother.
|Greg gets some fresh air.|
From "A Study in Pink," where Mycroft showed up at the scene of the killer cabbie's death, it can be assumed that Mycroft has someone inside Scotland Yard, keeping Sherlock busy and reporting on his whereabouts. It's Lestrade that uses Sherlock the most, and most likely it's Lestrade who is inside man.
The Reichenbach Fall 1
1 See opening of S02E02 "The Hounds of Baskerville."
2 See The Holmes Boys Stalking Moriarty