I'm a fake

J: Sherlock...

S: The newspapers were right all along. I want you to tell Lestrade, I want you to tell Mrs. Hudson and Molly; in fact, tell anyone who will listen to you... that I invented Moriarty for my own purposes.

J: Okay, shut up, Sherlock. Shut up. The first time we met - the first time we met, you knew all about my sister, right?

S: Nobody could be that clever.

J: You could.