DOCTOR: Hmm, there it is again. That itch. Go down, go down, go down, go down, go down.

IDA: The urge to jump. Do you know where it comes from, that sensation? Genetic heritage. Ever since we were primates in the trees. It's our body's way of testing us. Calculating whether or not we can reach the next branch.

DOCTOR: No, that's not it. That's too kind. It's not the urge to jump. It's deeper than that. It's the urge to fall.

DOCTOR: So, that's the trap. Or the test, or the final judgment, I don't know. But if I kill you, I kill her. Except that implies in this big grand scheme of Gods and Devils that she's just a victim. But I've seen a lot of this universe. I've seen fake gods and bad gods and demi-gods and would-be gods, and out of all that, out of that whole pantheon, if I believe in one thing, just one thing, I believe in her.

IDA: But Doctor, what did you find down there? That creature, what was it?

DOCTOR: I don't know. Never did decipher that writing. But that's good, Day I know everything? Might as well stop.

ROSE: What do you think it was, really?

DOCTOR: I think we beat it. That's good enough for me.

ROSE: It said I was going to die in battle.

DOCTOR: Then it lied.

DOCTOR: Maybe we opened the prison but not the cell.

IDA: We should go down. I'd go. What about you?

DOCTOR: Oh. Oh, in a second, but then again, that is so human. Where angels fear to tread. Even now, standing on the edge. It's that feeling you get, eh? Right at the back of your head. That impulse. That strange little impulse. That mad little voice saying, go on. Go on. Go on. Go over. Go on. Maybe it's relying on that. For once in my life, Officer Scott, I'm going to say retreat. Oh, now I know I'm getting old.

DOCTOR: I believe, I believe I haven't seen everything, I don't know. It's funny, isn't it? The things you make up. The rules. If that thing had said it came from beyond the universe, I'd believe it, but before the universe? Impossible. Doesn't fit my rule. Still, that's why I keep travelling. To be proved wrong. Thank you, Ida.

IDA: Don't go!

DOCTOR: If they get back in touch, if you talk to Rose, just tell her. Tell her. Oh, she knows.

DOCTOR: If you are the Beast, then answer me this. Which one, hmm? Cos the universe has been busy since you've been gone. There's more religions than there are planets in the sky. The Archiphets, Orkology, Christianity, Pash Pash, New Judaism, San Klah, Church of the Tin Vagabond. Which devil are you?

THE BEAST: All of them.

DOCTOR: What, then you're the truth behind the myth?

THE BEAST: This one knows me as I know him. The killer of his own kind.

DOCTOR: You get representations of the Horned Beast right across the universe, in the myths and legends of a million worlds. Earth, Draconia, Velconsadine, Daemos. The Kaled god of war. It's the same image, over and over again. Maybe that idea came from somewhere, bleeding through. The thought at the back of every sentient mind.

IDA: Emanating from here?

DOCTOR: Could be.

IDA: But if this is the original, does that make it real? Does that make it the actual devil, though?

DOCTOR: Well, if that's what you want to believe. Maybe that's what the devil is, in the end. An idea.