I'm sorry, Clara is dead. Kate Stewart is dead. The UNIT troops are all dead. Truth or consequences.

Bonnie

Clara: Oh my God, that's me.
Jac: I think we should wait.
Clara: Look, they're here. They're growing duplicates of us. We have to destroy them. I've seen this happen before. It happened to that little boy. They took his parents and then they took him.
Jac: But I don't see how these are duplicates. That's not how Zygons work. They don't grow duplicates. They kidnap the originals so, these... These are the humans!

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.

Doctor Who Quotes

Great men are forged in fire. It is the privilege of lesser men to light the flame. Whatever the cost.

Warrior Doctor

The Doctor: Clara? You asked me what we're going to do, I told ya. We're going to go to hell, or wherever it is people go when they die, if there is anywhere. Whatever it is we're gonna go there and we're gonna find Danny. And if it is in any way possible, we're going to bring him home. Every culture has a concept of an afterlife. I always meant to have a look around, see if I could find one.
Clara: You're going to help me?
The Doctor: Well, why wouldn't I help you?
Clara: Because of what I just did, I just...
The Doctor: You betrayed me. You betrayed our trust, you betrayed our friendship, you betrayed everything that I've ever stood for. You let me down!
Clara: Then why are you helping me?
The Doctor: Why? Do you think that I care for you so little that betraying me would make a difference?