Captain Jack: (about the Daleks) One minute, they're the greatest threat in the universe, the next minute they vanished out of time and space.
The Doctor: They went off to fight a bigger war. The Time War.
Captain Jack: I thought that was just a legend.
The Doctor: I was there. The war between the Daleks and the Time Lords, with the whole of creation at stake. My people were destroyed, but they took the Daleks with them. I almost thought it was worth it. Now it turns out they died for nothing.