River and The Doctor in “The Wedding of River Song”

Those reports of the sunspots and the solar flares, they're wrong. It's not the Sun, it's you. The sky is full of a million million voices saying, "Yes, of course we'll help." You've touched so many lives, saved so many people, did you think when your time came you'd really have to do more than just ask? You've decided that the universe is better off without you. But the universe doesn't agree.

River, no one can help me. A fixed point has been altered. Time is disintegrating.

I can't let you die!

I have to die!

Shut up! I can't let you die — without knowing you are loved — by so many, and so much — and by no one more than me.

River, you and I know what this means. We are Ground Zero of an explosion that will engulf all reality. Billions on billions will suffer and die.

I'll suffer, if I have to kill you.

More than every living thing in the universe?

Yes.