"Moony, what's this?" Sirius asked in an odd voice.
"What?" Remus called from the kitchen.
"This is a gun isn't it? One of those Muggle things for killing people?" Sirius's education in all-things-Muggle had included enough of the right kind of films for him to recognise one.
"Oh," Remus came around the corner into the bedroom, where Sirius sat on the bed, a wooden box open on his lap. He looked uncomfortable. "Yeah."
"Why do you have it?"
Sirius frowned "That's bollocks, Moony. These things are supposed to be nearly impossible to get in Britain, and I know how bloody strong you are. What d'you need protection for?" He lifted the revolver out of its box and flipped open the chamber. "There's only one bullet in here," he said, tipping it out onto his palm. "Moony -- this is silver."
Remus sat down heavily on the bed, not looking at him. "I've had it a long time. I thought one day I might -- need it."
"Why?" demanded Sirius angrily. "To off yourself?"
Remus did look at him then, eyes haunted. "What did I have left, Padfoot?" he asked softly. "Lily and James were dead. Peter, too, as far as I knew. And you -- " he sighed, shaking his head.
The gun dropped from Sirius's hand and clattered to the floor, forgotten, as he knelt before Remus, taking his hands between his own. "I'm sorry, Moony. I didn't mean to sound angry. I just -- I almost lost you all over again for a minute, you know? It's one more bad ending we might have had."
"I know." Remus's voice was hoarse. "But I didn't do it, because I didn't have nothing. Look again, Padfoot."
He handed the wooden box to Sirius, who turned it over in his hands. When he tipped it towards the light, he saw it.
"Oh," he breathed. "It says 'Harry' at the bottom."
"That's right," Remus smiled. "My fail-safe. If things ever got bad enough for me to open that box, Harry's name was right in front of me, to remind me why I needed to live."
Sirius set the box aside and gathered Remus into his arms.
"You made it, Moony. I'm so proud of you. You're the bravest Gryffindor of them all." He kissed Remus softly. "Remind me to thank Harry sometime."