After an hour or so, Hagrid and Slughorn began making extravagant toasts: to Hogwarts, to Dumbledore, to elf-made wine, and to—
“Harry Potter!” bellowed Hagrid, slopping some of his fourteenth bucket of wine down his chin as he drained it.
“Yes, indeed,” cried Slughorn a little thickly, “Parry Otter, the Chosen Boy Who—well—something of that sort,” he mumbled, and drained his mug too.
Not long after this, Hagrid became tearful again and pressed the whole unicorn tail upon Slughorn, who pocketed it with cries of, “To friendship! To generosity! To ten Galleons a hair!”
And for a while after that, Hagrid and Slughorn were sitting side by side, arms around each other, singing a slow sad song about a dying wizard called Odo.
“Aaargh, the good die young,” muttered Hagrid, slumping low onto the table, a little cross-eyed, while Slughorn continued to warble the refrain. “Me dad was no age ter go… nor were yer mum’ an’ dad, Harry…”
Great fat tears oozed out of the corners of Hagrid’s crinkled eyes again; he grasped Harry’s arm and shook it.
“Bes’ wiz and witchard o’ their age… I never knew… terrible thing… terrible thing…”
“And Odo the hero, they bore him back home To the place that he’d known as a lad,”
Sang Slughorn plaintively.
“They laid him to rest with his hat inside out. And his wand snapped in two, which was sad.”
“…terrible,” Hagrid grunted, and his great shaggy head rolled sideways onto his arms and he fell asleep, snoring deeply.
“Sorry,” said Slughorn with a hiccup. “Can’t carry a tune to save my life.”
“Hagrid wasn’t talking about your singing,” said Harry quietly. “He was talking about my mum and dad dying.”
“Oh,” said Slughorn, repressing a large belch. “Oh dear. Yes, that was—was terrible indeed. Terrible… terrible…”
He looked quite at a loss for what to say, and resorted to refilling their mugs.
“I don’t—don’t suppose you remember it, Harry?” he asked awkwardly.
“No—well, I was only one when they died,” said Harry, his eyes on the flame of the candle flickering in Hagrid’s heavy snores. “But I’ve found out pretty much what happened since. My dad died first. Did you know that?”
“I—I didn’t,” said Slughorn in a hushed voice.
“Yeah… Voldemort murdered him and then stepped over his body toward my mum,” said Harry.