(Harriet Jones orders an attack at the Sycorax's ship, making the ship explode over the Earth...)

Doctor: That was murder.

Harriet Jones: That was defense. It's adapted from alien technology. A ship that fell to Earth ten years ago.

Doctor: But they were leaving.

Harriet Jones: You said yourself, Doctor, they'd go back to the stars and tell others about the Earth. I'm sorry, Doctor, but you're not here all the time. You come and go. It happened today. Mr. Llewellyn and the Major. They were murdered. They died right in front of me while you were sleeping. In which case, we have to defend ourselves.

Doctor: Britain's golden age.

Harriet Jones: It comes with a price.

Doctor: I gave them the wrong warning. I should have told them to run as fast as they can. Run and hide because the monsters are coming. The human race.