Clara: You're always talking about what you can and can't do, but you never tell me the rules.
The Doctor: We're time travelers. We tread softly. It's okay to make ripples, but not tidal waves.

Go. Now. Go find Vikings on other planets. The universe is full of testosterone. Trust me, it's unbearable.

Clara

Winning is all about looking happier than the other guy.

The Doctor

A good death is the best anyone can hope for, unless you happen to be immortal.

The Doctor

What is a God but the cattle’s name for farmer? What is heaven but the gilded door of the abattoir?

Odin

I looked them up in my 2000 year diary. They are called The Mire. They are one of the deadliest warrior races in the entire galaxy, but they're practical. They get what they want and then they go.

The Doctor

Ashildr: You think they're all idiots, don't you?
The Doctor: What, you mean the rest of the universe? Basically, yes I do.
Ashildr: But they're kind and brave and strong. And I love them.
The Doctor: Good, but that won't save you.

Doctor Who Season 9 Episode 5 Quotes

Go. Now. Go find Vikings on other planets. The universe is full of testosterone. Trust me, it's unbearable.

Clara

Clara: You're always talking about what you can and can't do, but you never tell me the rules.
The Doctor: We're time travelers. We tread softly. It's okay to make ripples, but not tidal waves.