SLASH: M/M There are ways of coming back. Slash future-fic, Bring Back Black, rating for a tiiiny bit of language, and pretentious as all get-out. Spoilers if you're only familiar with the movies.
Harry had to look through a lot of boxes, but he found the book and owled it to Remus. There weren't any more owls from the continent after that.
Then it was late in January and Remus was in Harry's living room, a glass sarcophagus on the floor in front of him with a snow-pale body inside and melting frost on the panes. "Only one spell left," said Remus, even as he fell asleep on the couch. He slept three days and the frost never quite finished melting, even though Harry had the room as hot as it had ever been. Such old spells as those on the sarcophagus are never broken so easily.
Remus woke up and far more people than necessary were in the living room, too, comrades and friends and not-quite-family from the last war, which meant there was pressure to not look like an idiot, but it was far too late to worry about that sort of thing. He removed the lid and reached through the sudden fog of sublimating frost, pulling the cold body up into his arms.
"Come on then, time to wake up, you queen," and then his lips against the mouth that, in thawing, was red like blood: the breath of life, the pilot light soul, revival at its most happily-ever-after. The last shards of ice dropped from strands of black hair.
"I'm fucking cold," Sirius said.
Harry brought him a blanket.