Dumbledore's farewell letter to Snape. Implied SS/HG and character death. Written pre-HBP.
Funny, I never saw it coming. Still, I know I can trust you as I always have, even if nobody else will do so.
As to Potter, I know you still despise him, but understand, he no more chose his lot than you did. I ask that you accept him, for Hermione's sake, if not my own.
My final wish is that you and she act on your growing affections. See it as an opportunity, Severus, to start life anew. Perhaps a family is in order, now that the darkness has ended.