SuperWho AU! where Amy sacrifices herself to save Sam.
"That’s why humans are idiots, you know? They sacrifice themselves for love and for those other stupid things. You know the penalty, don’t you, dear Amy? Burn in Hell for eternity. Would you do something so radical to save a person who is already doomed as Sam Winchester? Oh, well, you, humans, always so sentimental, passionate and absurdly pathetic. If you’re so determined, lucky me. It will be a pleasure doing business with you."