Here via Torino10154's rec....
This is not a pairing I would have ordinarily read - but Torino's recs are worth pursuing, and I'm very glad I did. After completing the story, I still wouldn't describe the pairing as a favorite - and yet, I was cheering as loudly for Slughorn's success as any Slughorn shippper could! Beautiful - you certainly made this pairing work for me in this fic. And your characterization of Slughorn is magnificent!!! Acknowledging his faults, and yet giving him such depth - his regrets and resignations enrich a character who might otherwise be shallow - and honestly, I liked him from the moment I read: He drank to the most cunning, two-faced, duplicitous snake of a Slytherin he had ever had the pleasure of knowing. Magnificent. The quality of writing here is splendid, mystery author - so much to enjoy and savour - Whoever said that time healed all wounds had either lived to an astonishing age or was in fact a gibbering idiot. Time healed nothing. Days and months and years were lazy thread work, and all it took was the gentlest flex of memory to burst the stitches open again. - truly memorable lines. And He left him there that night, alone amidst his eldritch studies. Three years later, he would leave his comfortable position at Hogwarts, unable to face another class of fresh-faced first years, unable to befriend another upperclassman who might yet be a murderer. He had taught his students that the world was theirs for the taking, and they had taken it. He had taught them there were no odds they could not surmount, and they had stood up to terrorism, fought, and fallen.
It would be another twenty years before he would wonder what would have happened if he had imparted a little confidence in just one more boy. is worth reading the story for alone, even if you hadn't made it already so marvelous in so many ways. Thanks for sharing, mystery author - a truly wonderful story!