Ultron: How could you be worthy? You're all killers.
Steve Rogers: Stark.
Tony Stark: Jarvis?
Ultron: I'm sorry, I was asleep. Or I was a-dream.
Tony Stark: Reboot Legionnaire OS. We got a buggy suit.
Ultron: There was this terrible noise. And I was tangled in... In... Strings. I had to kill the other guy. He was a good guy.
Steve Rogers: You killed someone?
Ultron: Wouldn't have been my first call. But, down in the real world, we're faced with ugly choices.
Thor: Who sent you?
(Ultron plays a recording of Tony's voice: "I see a suit of armor around the world.")
Bruce Banner: Ultron.
Ultron: In the flesh. Or, no, not yet. Not this chrysalis. But I'm ready. I'm on mission.
Natasha Romanoff: What mission?
Ultron: Peace in our time.
(Some fighting later...)
Ultron: That was dramatic. I'm sorry, I know you mean well. You just didn't think it through. You want to protect the world but you don't want it to change. How is humanity saved if it's not allowed to... evolve? With these? These puppets. There's only one path to peace. The Avengers' extinction. (Thor breaks Ultron's suit) I had strings, but now I'm free.