I know about poisons Watson, actually all about them. Over the past few years I've come to learn the worst kind, Guilt.

Sherlock

You, ummmmm...., saved me. I'd like to return the favor.

Sherlock

Sherlock: Most importantly, he understands you. He understands you and me.
Watson: What do you mean by that?
Sherlock: I mean, Watosn, whether you care to admit it lately or not, I am an important part of your life. Whether I say it out loud or not, you are an important part of mine. My return to New York was driven in large part by my desire to repair our relationship. I think even though we might draw further or nearer from each other, depending on circumstance, you and I are bound, somehow. Andrew accepts that without feeling needlessly threatened. It's a rather enlightened position.

I don't understand the questions. Could I have more information?

Bella

What's up with the nerd brigade?

Joan

You, Watson, are not people. Neither was Kitty.

Sherlock

What do you say, Watson? Will you help?

Kitty

Don't talk twaddle … I just want to maintain focus.

Sherlock

Harlan: You were my friend.
Sherlock: I was your employer, Harlan. And you were my consultant. One of many.
Harlan: I know that I am a little obsessed with what I do. That has always made it hard to make friends. And I used to feel pretty bad about that and then I meet you. And I thought to myself, hey, if it doesn't bother him, why should I let it bother me? I got a lot out of the work we did. A lot. But if someone like you, thinks I'm a loser, then ...

Bell: What am I missing?
Holmes: Everything that matters.

I sort of travel in different mathematical circles...

Harlan

In the wrong hands, math can be manipulated, abused. I decided to do something about it. You catch people who murder other people. I catch people who murder math.

Harlan