The Doctor: Which one are you? Human or Zygon?
Osgood: I don't answer that question.
The Doctor: Why not?
Osgood: Because there is no question to answer. I don't accept it.

Kate: You left us with an impossible situation, Doctor.
The Doctor: Yes I know, it’s called peace.

Any living thing in this world, including my family and friends could turn into a Zygon and kill me. Any second now. It's not paranoia when it's real.

Walsh

Clara: So Osgood's been kidnapped, right? I thought Osgood was dead.
Kate: There have always been two of her, ever since the cease fire. We never knew which one was real.
The Doctor: Both of them.
Kate: Okay, which one was Zygon.
The Doctor: Both of them. They would have maintained a live link. They were both Zygon and human at the same time.

Osgood 1: The Zygons are a peaceful race.
Osgood 2: Their shape changing abilities should not be considered a weapon.
Osgood 1: It's a survival mechanism.
Osgood 2: They embed themselves in other cultures and live out their lives in their new bodies, in peace and harmony. Mainly.

Enemies are never a problem. It’s your friends you have to watch out for.

Me/Ashildr

Me/Ashildr: You've had an impact on this world. You've made waves.
The Doctor: Sometimes tidal waves.
Me/Ashildr: I'm flattered.

You didn't save my life, Doctor. You trapped me inside it.

Me/Ashildr

Sam Swift: Who's this, your sidekick? You got your dad as your sidekick?
The Doctor: I'm not his dad, I'm the Doctor.
Sam Swift: Is that the best name you could come up with?
The Doctor: What, says Sam Swift the Quick? Trying a bit too hard, isn't it?

The Doctor: Why are you still alone? What happened to the second immortality charge I gave you?
Me/Ashildr: No one's good enough.

The Doctor: His life force is opening a portal.
Me/Ashildr: To my new life.
The Doctor: Or to Hell.

The Doctor: Ashildr.
Me/Ashildr: That's not my name. I don't even remember that name.
The Doctor: Well, what do you call yourself?
Me/Ashildr: Me.
The Doctor: Yes. You. There's nobody else here.
Me/Ashildr: No. I call myself, Me. All the other names I chose died with whoever knew me, Me is who I am now. No one's mother, daughter, wife. My own companion. Singular. Unattached. Alone.

Doctor Who Quotes

You're going to fire me at a planet? That's your plan? You're going to fire me at a planet and expect me to fix it?

Doctor Who

I made you a souffle, but it was too beautiful to live.

Oswin