The Chocolate of the Afterlife by bonfoi, House Hufflepuff
When Remus saw the Light, he turned back to find Severus. Missing him, he went searching, plunging through, witch, wizard, and wall until he flew into the boatshed and found Severus' barely twitching body.
He reached into his ghostly pocket and pulled out a half-eaten bar of Honeyduke's Darkest, incidentally Severus' favorite indulgence, aside from frotting in dark corners where anyone could find him, if only they looked.
He waved the ephemeral bar under Severus' nose until he drew forth, not a sigh, but a gust of ectoplasmic goo. Severus' spirit seeped out of his nose and reformed itself at Remus' side. While his neck was reddened, the wound was no longer gaping.
"You entice me with the memory of chocolate, Lupin?" Severus might be dead, but his hauteur was intact; he looked down his nose at Remus still kneeling at his body's side. "Why did you think that would work?"
"I didn't," Remus said with a laugh as he stood up. "I just wanted to see if you wanted to scare the Hogwarts' ghosts once more, this time by having a fine old time from one of the chandeliers." He tucked the rewrapped chocolate into his robes.
"Hm, that would be interesting." Severus began drifting toward Hogwarts. "Do you think the Grey Lady would be keen on watching or participating? I've often wondered what it would take to make her speak." They wafted into and out of each other, finally disappearing as the fog from the Black Lake rose.
"Do you think we'll shock anyone living, Lupin?" Severus asked.
"If you're thinking of finding Harry, I refuse. That would be almost incestuous."
"Well, then, the Grey Lady it is. Unless you've got an idea about how to interest the Bloody Baron in a threesome?"