Do you want to hear about the deal that I'm making?
A couple of weeks ago, my mother decided to follow her Harry Potter re-read with a rewatch or in some cases first watch of all the movies; I came in at Harry Potter and the Prisoner of Azkaban (2004) and we finished both parts of Deathly Hallows (2010/2011) last night. I had forgotten that even with all the compression and elision of film vs. book, I still find the post-mortem montage of Snape's memories devastating. All those past impossibilities, all that unredeemable time; like being fanned a hand of alternate histories, but nothing in a dead man's memories can be changed. The film omits one point I really would not have glossed because of its importance to both Lily and Severus—that their friendship doesn't end because she starts dating his bully, but because he starts hanging out with magical neo-Nazis—but then it invents something that hurts so much it feels like it must be true: that Snape was the one to discover the carnage at Godric's Hollow, his old rival dead on the stairs and his dearest love in the nursery where she died for the child now crying in his crib as Snape cries among the shattered plaster on the floor, rocking the lifeless body of Lily Potter in his arms. They look like a bereaved family. They are, kind of. They aren't. Snape could never have raised Harry even if he hadn't needed to preserve his appearance of loyalty to Voldemort, which I suspect even his formidable skills at double-agenting could not have kept up with a baby in the picture; he didn't share Lily's blood that shielded Harry at the Dursleys' and I am aware of the understatement when I say that he wasn't good with children. He becomes one of Harry's parents all the same, the one Harry doesn't know about, the one who literally died before he let anyone know. The silver doe bounding through Dumbledore's office could have been pathetic: clinging to a ghost. It's the one part of himself Snape can't lie about. It's a powerful emblem of love.
I am sure that eight years ago everyone already thought of vidding Snape's history to "Running Up That Hill (A Deal with God)," but here we are. I am very prosaically going to walk to a grocery store.
I am sure that eight years ago everyone already thought of vidding Snape's history to "Running Up That Hill (A Deal with God)," but here we are. I am very prosaically going to walk to a grocery store.

no subject
I'm not sure that's at odds with my original statement. Snape doesn't just give his life for someone he can't stand who hates him, he entrusts it to that same someone. There's an astonishing bravery and vulnerability in that. He lets himself be seen wholly by someone who might learn all his secrets and still hate him—the equivalent of the fans who argue that Snape can never be truly redeemed. (It is not a relevant question for me, for the record; it's not a concept I find very useful in either my life or my fiction. Atonement and restitution make a lot more sense to me. I find Snape to fulfill those conditions. Is it enough? How would I know? It's what he could do.) At the same time, there's no more important person who could see him than Harry. The stakes are high and complicated and all of this in a man who for all his life-saving spy's self-control has canonically never handled vulnerability—it usually comes tied up with mockery—well. Knowing it had to be done, like just about everything else in Snape's life since the death of Lily, can't have made it easier.
This guy is one for the ages. I like smart grumps.
They are excellent.