* Moriarty's true identity is revealed: The episode revolves around Sherlock trying to decipher a series of riddles and games set by his nemesis, Moriarty. At the end, Sherlock realizes Moriarty is behind everything, and the camera pans up to show Moriarty's face on a giant screen at the top of a building.
* Moriarty makes his demands: Moriarty publicly announces that he knows Sherlock's true identity and reveals he has planted bombs around London. He gives Sherlock a list of people he must kill, and he'll disarm the bombs. This creates a chilling ultimatum.
* Sherlock's desperate choice: Knowing he can't kill innocent people, Sherlock realizes he has to play along with Moriarty's game. He takes a photo of Moriarty with his phone, knowing he can use it to track him down.
* A tense ending: The episode ends with Sherlock staring out a window, knowing he's now in a deadly game with a cunning and powerful enemy. He realizes that he can't rely on anyone but himself.
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