The Doctor and Dockery in “A Town Called Mercy”

How old are you?

Nearly 19.

That's 18, then. Too young to have fought in the war, so I'm guessing you've never shot anyone before, have you?

First time for everything.

But that's how all this started. Jex turned someone into a weapon. Now that same story's gonna make you a killer, too. Don't you see? Violence doesn't end violence, it extends it. And I don't think you want to do this. I don't think you want to become that man.

There's kids here.

I know, who I can save, if you'll let me.

[Nodding to the building holding Kahler-Jex] He really worth the risk?

I don't know. But you are.

Frightened people. Give me a Dalek any day.