CW: research, chosen families, marriage, custody

:THIRTY-SIX:

And then, once again much too soon, Remus and Sirius had to take Harry back to school. Waving him off on the train platform, Sirius heaved a great sigh.

"Back to the grindstone, Remus." He said, looking grim even as he said it.

"Yeah," Remus frowned. "You know, perhaps we should sort out books and then bring them back to the flat? I know how that place gets to you."

But Sirius shook his head. "I don't want to accidentally bring something bad over to our flat."

Remus nodded, reaching out to hold Sirius' hand.

"Okay," He agreed. "But then you have to promise to tell me when you need us to leave or take a break."

Sirius smirked at Remus, but it didn't quite reach his eyes.

"Always so bossy, Remus."

"Always," Remus grinned. "Ready?"

Sirius nodded, and Remus apparated them back to 12 Grimmauld Place.

It was just as dark and terrible as before, but almost worse now that Kreacher wasn't there. They'd both agreed not to bring him back, since they knew the portrait of Sirius' mother would just scream at the elderly elf if she ever saw him again. And for all Kreacher pretended, he was too old and fragile to handle an interaction like that.

The two men quietly walked up the stairs to one of the empty studies. They'd been using this room previously for their research on the Chamber of Secrets, and there was clear evidence of that research on every spare surface. Books stacked impossibly high and messy papers everywhere, with the curtains thrown wide open to cast light on the otherwise dark room.

"Well," Remus said, hands on his hips. "We probably ought to clean this up first."

Sirius tapped his chin thoughtfully. "Actually, I think we can use some of this information."

When Remus looked at him questioningly, Sirius explained.

"We're trying to make a timeline of Voldemort, right? Well, we've got a huge portion of it right here. Maybe we can trace the ancestry between Salazar Slytherin and Voldemort to find his family?"

Remus shuddered. "It's hard to imagine Voldemort having a family."

"Well," Sirius said resolutely. "He had to have one at some point. And who they are is somewhere in this mess."

They split tasks, Sirius taking out all of the snake-related knowledge and putting it in one corner of the room. It was much less likely, they reasoned, that there would be another direct connection to Voldemort through magical snakes. Remus took over Salazar Slytherin's history, separating their knowledge into a chronological order. Now that they had a fairly good base for the founder himself, they needed to trace his legacy through wizarding kind.

By the time the sun had begun to set outside, they had a semi-organized platform on the floor. Looking over their work, both men felt decently proud of themselves.

"You know," Remus thought aloud. "We should get some sort of board to work on. We're not as young as we used to be, and the floor is an awful long way down."

Sirius barked out a laugh, clapping Remus on the shoulder.

"Anything for you, love. Now come on or Kreacher will murder us for being late again."

Remus let out an involuntary shudder. They'd been late to supper once, and Kreacher had burnt their breakfast for a week.

This pattern continued for the following months. While Harry wrote to them about his classes and quidditch practices, Remus and Sirius spent their days researching for ways to keep Harry safe. They'd compiled a pretty decent-looking family tree based on their research, which they'd pinned up on one corner of a very large corkboard.

Sirius had also begun researching items Salazar Slytherin held dear besides the locket. It was just a hunch, but Sirius suspected that maybe Voldemort would have used another Slytherin heirloom for a horcrux. Not that he could imagine making more than the two that were already destroyed. After Dumbledore's description of what a horcrux was and what it required to make, Sirius tried his best not to think too much about how gruesome it must have been.

So the corkboard also had a section on various magical objects Salazar Slytherin was pictured with or spoke of in his many references to wizarding texts.

Remus, on the other hand, took more interest in the people Voldemort surrounded himself with during his time as a dark lord. Any of the Death Eaters could have potential information they could use. Dumbledore already suspected that the diary horcrux had been in Malfoy's possession before it made its way into Hogwarts, so it stood to reason that Voldemort may have done the same with others.

He'd made a long list of names, which were pinned up in order along with a blank space for written follow-up. He didn't include the ones he knew were already dead, but did include all of the ones currently in Azkaban. He had no idea how they could possibly reach them, but maybe Dumbledore would be able to arrange something.

Overall, the two men felt very proud of their work by the time summer had rolled around. They hadn't heard anything from Dumbledore, but they also didn't feel comfortable sending the information they had gathered in a letter. So instead, they chose to just write that they would wait for his owl and collaborate in person.

"I don't think there's much else we can research." Remus mused, looking over the room and their monstrous corkboard.

Sirius nodded, stretching his arms over his head. "Besides, Harry will be home soon."

"That's true." Remus turned to smile at Sirius. "And we still have to figure out the last name situation."

They'd been going back and forth on this for a while. Either Remus would take official guardianship of Harry and change their last names, so Sirius would take the last name when they got married, or vice versa.

"I'm the one who proposed!" Sirius immediately said, entering into the old banter. "So Harry should be my kiddo and you take our name!"

"Ah," Remus said, smirking. "But I raised Harry for longer, love. And who is the one called 'Papa'?"

Sirius rolled his eyes. "Oh, not that again!"

They bantered all the way back home, continuing to flirt all through their last evening alone together. Only after they had collapsed together in bed did the conversation turn more serious. Remus was stroking Sirius' curls, watching them bounce back every time he brushed them out.

"I think you should take Harry's guardianship," Remus murmured. "It's what James would have wanted - he did name you godfather."

Sirius looked up at him, a gentle smile on his face. "Are you sure?"

"Yes," Remus nodded. "Plus, I don't mind my last name as much as you mind yours. I can wait until our wedding to change mine."

A shadow seemed to fall over Sirius' face at these words, but Remus kissed them away.

"Alright, alright." Sirius laughed. "I can't wait to tell Harry."

Notes:

Hullo! I'm still hoping for more feedback on the last name situation, which will be decided next chapter.

Happy Reading!