Gwen: They move the category ones at 6am. They take them to the module--
Dr. Patel: Sorry. Not my department.
Gwen: Really? Is that so? Well do you even know what your department is, Dr. Patel? Do you even know what really happens here? Do you know what happens in the module?
Dr. Patel: Like I said, I'm rather busy.
Gwen: They burn people. They burn living people.

Gwen: They've got my dad, Jack. They've got my dad.

Gwen: This lemonade. This lemonade's flat.
Esther: It's lemonade. It's supposed to be flat.
Gwen: What? Fizzy, fizzy lemonade?
Esther: It's fizzy in the UK and flat in the US.
Gwen: Hmm. Just about sums it up.

Gwen: What sort of getaway car is this? I thought you Americans all had these big SUVs. This is rubbish!
[after seeing Lyn's body with her head twisted around 180 degrees]

Gwen: When I was about 5 or 6, my dad came home from work early. And I knew there was something wrong, I could hear voices from the kitchen. So I looked through the door and I could see him crying. Turned out money'd gone missing from work and he got the blame. So I went to get all my pocket money and I put it in his hand. Must have been about two pound fifty. He looked at me and said it wasn't about the money. He said "I can't stand anyone thinking I'm not an honest man," and I've always remembered that. Always. Because that was the first time in my life anybody had spoken to me like an adult. And then we went to the back garden and we played until dark. So that's my dad. Geraint Wynn Cooper, the nicest man in the world. And today's the day that I kill him.

Gwen: You watching?
Jack: I'm here. And I've opened up the radio link. Make your message.
Gwen: This is the truth for the whole world to see. We let our government build concentration camps. They built ovens for people in our names. Now I don't care if the whole of society bends over and takes this like a dog. I'm saying, No. [she blows the complex]
Jack: That's my girl.

Gwyn: That's what the modules are. They're ovens. They're burning them. The patients They're burning them alive.

Jack: [after Gwen tries an American accent] You're so never doing that accent again.

Jack: End the miracle. And you can die. You're cursed with intelligence. Clever enough to know who you are. And wise enough to want it to end. You help me and I promise I will help you to die.

Jack: I saw you on television, saying you feel forgiven for taking the life of a child. That's a lie. I know that's a lie.
Danes: How do you know that, Jack, with such certainty?
Jack: Tell the truth! The murder of Susie Cabena. You don't feel sorry at all.

Jack: I was thinking. About how you're immortal. And I'm dying. And what I wanted to say was... we're good aren't we? You and I? Good team. I missed you.
Gwen: I was thinking that, ah, if this had happened a bit sooner...
Jack: I know.
Gwen: He'd still be here, Ianto.
Jack: Dead friends.
Gwen: I'm sorry.
Jack: I wish he was here now. Not much of a team, is it? But we've still got each other. You and me. Just like the old days.

Jack: I'm going with you. I don't know, I could be your... assistant.
Esther: We told you, not a chance. That assassin said that you're too connected. And besides, you're too fragile, Mortal Man. [she kisses him on the cheek]
Jack: All I get is a kiss?
Esther: You look after yourself. You're unique. You're Category Jack.

Jack: Our greatest problem is that what's happened to the world is invisible. Quite by chance Oswald's found himself right at the heart of it. George Elliot wrote this chapter in Middlemarch. She said that if you take a piece of metal with random scratches all over it and hold a flame up to the metal, the scratches look like they're forming patterns. Circling around the light. And that Oswald. He's blazin' away. The patterns are starting to revolve around him. And all we have to do is keep watching.

Jack: So that means everyone's to blame. Everyone and no one.
Stewart: Whoever's behind this, they don't show themselves. Not to me, not to you. But to play the system like this--the markets, the politics, industry--they had to be planning this for a very long time. I wish I knew who they were.

Jack: The amazing thing about the miracle is not that no one's dying, it's not that the human race has become immortal. It's that it happened to everyone at the same time. Don't you see? It was instantaneous and that's a morphic event on a scale that I have never seen before. So whatever's happening to this planet, it is massive!