For the moment, with the narration's apologies, Buffy's forgotten. Because Dean has taken in what his brother has said, all of it. Especially that last bit.

Dean cannot imagine an existence without Sam. He sold his soul to get his brother back. The idea of him--even if it's some other him, out there in some other universe or crazy city or whatever the hell is going on--having to exist without his brother... even the thought chills him.

"...I hope he's okay back there."