Madness is just what a genius looks like to a tiny mind.

If anyone said to me 'invent a new monster so we can sell more toys', I'd kick them out of my office.

If it’s time to go, remember what you’re leaving. Remember the best.

So is this how it works Doctor? You never interfere with the affairs of other peoples or planets, unless there are children crying?

I'll be a story in your head. But that's OK. We're all stories, in the end. Just make it a good one, eh? Because it was, you know; it was the best.

The Doctor: [aiming gun at the ceiling] Didn't anyone ever tell you? There's one thing you never put in a trap if you're smart. If you value your continued existence, if you have any plans about seeing tomorrow, there's one thing you never, ever put in a trap. Angel Bob: And what would that be, sir? The Doctor: Me. [fires]

What is immutable about Sherlock Holmes? He favors reason over emotion, but actually underneath that, there is a lot of emotion going on. You can't suddenly make him ordinary because he would hate that. He's not suddenly going to be somebody else.